H2 and H2S gases were detected for thefirst time by utilizing lead-free perovskites, and ultrasensitivedetection of NO2 was also achieved at room temperature.In addition, the band-gap type, defect tolerance, and electronic surfacetraps at the nanocrystals were studied in detail for understandingthe differences in the sensing performance observed. Finally, a comprehensivesensing mechanism is proposed.Lead halide perovskites have been attracting great attentiondueto their outstanding properties and have been utilized for a widevariety of applications. However, the high toxicity of lead promotesan urgent and necessary search for alternative nanomaterials. In thisperspective, the emerging lead-free perovskites are an environmentallyfriendly and harmless option. The present work reports for the firsttime gas sensors based on lead-free perovskite nanocrystals supportedon graphene, which acts as a transducing element owing to its highand efficient carrier transport properties. The use of nanocrystalsenables achieving excellent sensitivity toward gas compounds and presentsbetter properties than those of bulky perovskite thin films, owingto their quantum confinement effect and exciton binding energy. Specifically,an industrially scalable, facile, and inexpensive synthesis is proposedto support two different perovskites (Cs Therefore, there is a growing demandfor novel miniaturized affordable and reliable devices that are ableto detect pollutants at trace levels. Devices that are able to implementreal-time monitoring of the air quality for raising an alarm whenpollutants exceed the threshold limit values (TLVs) are much sought.In this sense, the environmental monitoring market is estimated togrow at a compound annual growth rate (CAGR) of 4.5% to reach USD17.98 billion by 2026.2 Within this market,the air quality monitoring market size was valued at over 3.5B in2018 and is expected to grow at a 7% CAGR. In consequence, to achievelarge gas-sensor networks, there is a growing demand for developingcost-effective devices. Despite some instrumental techniques as gaschromatography or surface-enhanced Raman spectroscopy (SERS) beingextremely sensitive, selective, and accurate, significant drawbacksare preventing their widespread distribution over large areas. Thisis because these techniques are bulky and costly and require trainedpersonnel, and real-time monitoring is still a challenge.4Air pollution, defined as therelease of harmful gases into the atmosphere, is becoming a majorsocietal concern due to its effects on human health and the environment.In addition to the acute exposure to gases in leakage events, long-termexposure to low concentrations of pollutants can induce significantrespiratory and cardiovascular health issues, resulting in millionsof premature deaths yearly.5 With all of that, chemoresistors are interesting candidatesfor developing the new generation of unattended and ubiquitous gas-sensingnetworks. However, for a feasible spatial distribution of battery-poweredmonitoring nodes, low-power consumption devices, which can be achievedby developing room-temperature sensors, are needed. Chemoresistorsbased on metal oxides (MOXs) have received large research effortsduring the last decades owing to their high sensitivity and fast adsorption/desorptionof gas molecules dynamics.6 However, MOXgas sensors usually require high operating temperatures to activatetheir sensing properties and show limited selectivity,7 which can prevent their effective implementation in commercialdevices. The reason is that the high temperatures needed significantlyincrease the energy consumption and increase the fabrication costssince heating elements and temperature controllers are required. Additionally,high operating temperatures can compromise the long-term stabilityand repeatability, owing to phase, morphological, or even compositionalchanges in the nanostructures. For instance, coalescence effects onMOXs can modify the structures, resulting in their agglomeration inlarger entities and therefore altering their sensing performance.Within the different sensing devices, chemical resistive sensors(chemoresistors) have emerged as an interesting technology due totheir ease of use, inexpensiveness, stability, and suitability forminiaturization and implementing real-time monitoring.8 Conversely, pristine graphene tends to show significantdrawbacks that are preventing its effective implementation in commercialdevices. Its rather inert surface and poor specificity result in lowsensitivity and selectivity, respectively. Within this perspective,graphene surface modification is a feasible strategy for improvingsensing performance. Different approaches as graphene decoration withmetal or metal oxide nanoparticles have been shown to be good optionsfor enhancing sensitivity and, to some extent, selectivity.5 However, the resulting hybrid nanomaterials usuallyrequire applying relatively high operating temperatures, challengingthe capability of graphene to work under room conditions.Thereby, recent research efforts have been focused on the developmentof sensitive layers that are able to be operated on under room-temperatureconditions. Within the different available nanomaterials, graphenehas emerged as a promising candidate owing to its outstanding properties.For instance, graphene virtually shows the highest surface area-to-volumeratio, resulting in a larger area exposed to the environment for interactingwith gas compounds. In addition, graphene shows low noise levels owingto the high carrier density and mobility, while its synthesis at anindustrial scale has an affordable production cost.9 Like graphene, thesenanocrystals can be used for sensing purposes at room temperature,revealing a suitable alignment between the requirements of both nanomaterials.In this sense, the creation of hybrids combining graphene and perovskitenanocrystals led to low-power and inexpensive gas sensors owing totheir room-temperature operation. Furthermore, their combination presentsan interesting synergistic effect.10 Onthe one hand, the high chemical reactivity of halide perovskite improvesthe low sensitivities obtained using pristine graphene, and on theother hand, the instability of halide perovskites in the presenceof ambient moisture is well known,11 whichresults in a fast degradation. However, the high hydrophobic characterof graphene can protect the perovskite nanocrystals against ambientmoisture, increasing their stability and enabling their use in ambientmonitoring applications. In addition, the use of perovskite nanocrystalspresents better optical and electrical properties compared to thebulk phase. This is due to their tunable size and high quantum confinement.12 Nevertheless, despite the outstanding sensingperformance in using halide perovskites, most of them use lead (Pb)as a divalent cation. Their manipulation and use in synthesis protocolsinvolve severe risks to human health and detrimental environmentaleffects. Lead exposure, even to low concentrations, can significantlyaffect the cardiovascular and neurological systems.13 Therefore, the use of lead is progressively restrictedby the authorities, even in electrical and electronic systems. Inconsequence, despite the noteworthy properties of lead halide perovskites,their effective implementation in commercial devices is limited.Alternatively,nanomaterials such as lead halide perovskite nanocrystalshave been used for decorating graphene and consequently improvingsensing performance.14 Nevertheless, this paper reports for the first time a comprehensivegas-sensing study of nanohybrids based on different lead-free perovskitessupported on graphene. A green-chemistry and environmentally friendlyapproach is proposed for developing durable, reproducible sensitivegas sensors using novel perovskites. Two perovskite NCs have beenstudied: (a) Cs3Cu2Br5 characterizedby its direct band gap, outstanding stability, and nontoxicity ofCu(I) and (b) Cs2AgBiBr6 with its indirect bandgap, nontoxic character, and remarkable thermal and environmentalstability.16 These perovskites were supportedon graphene for detecting a wide variety of gas compounds such asNO2, NH3, H2S, and H2.As a result, the highest sensing performance of lead-free perovskites was obtained to date. In addition,the graphene-supported lead-free perovskites show even higher gas-sensingperformance than that of graphene-supported lead halide perovskites.Therefore, the method proposed leverages the high versatility of perovskitesand their straightforward synthesis and integration into transducingsubstrates, which can be easily exported to a large-production scale.For that reason, very recently, some research efforts have redirectedtoward the use of lead-free halide perovskites for reducing the potentialdangerousness and retaining their excellent properties. This typeof perovskites has been reported for a wide variety of applicationssuch as photodetectors, solar cells, and LEDs.3CuBr5 and Cs2AgBiBr6) were synthesized through hotinjection methods.18 Both synthesis processes requireda first step for obtaining the cesium oleate, which was prepared byadding 0.814 g of Cs2CO3, 2.5 mL of oleic acid(OA), and 40 mL of octadecene (ODE) in a 100 mL three-neck flask.The mixture was kept at 120 °C under vacuum for 1 h, and afterward,the temperature was increased to 150 °C under a nitrogen atmospherefor achieving the complete solubilization of Cs2CO3. Then, the Cs–oleate solution was cooled down untilroom temperature by switching off the hot plate, resulting in theprecipitation of the Cs–oleate and the ODE as a supernatant.In the next synthesis steps, the Cs–oleate will be preheatedto 100 °C before injection.Two lead-free perovskite nanocrystals  were added under a nitrogen atmosphere. When the complete solubilizationof CuBr2 was achieved, the temperature was increased to160 °C, and 6 mL of the Cs–oleate previously obtainedwas quickly injected. After 5 s, the reaction mixture was cooled downusing an ice-water bath, inducing the nanocrystals’ precipitation.Finally, a centrifugation process (6000 rpm for 5 min) was performedfor extracting the nanocrystals, which were redispersed in isopropanol,resulting in a stable perovskite solution.Cs2AgBiBr6 NCs were obtained by adding BiBr3 (45 mg), AgNO3 (17 mg), and HBr (100 μL)to 4 mL of ODE, and the solution was heated under vacuum for 1 h at120 °C. Once the complete solubilization was achieved, the solutionwas further heated up to 200 °C under a nitrogen flow and 0.8mL of the Cs–oleate was injected. Afterward, the mixture wascooled by using an ice-water bath after 5 s. The NCs were obtainedafter a centrifugation process (7000 rpm for 10 min) and were finallyredispersed in isopropanol and washed several times.Cs3Cu2Br5 and Cs2AgBiBr6 NCs were added (5% wt.) to graphene solutions.For achieving a suitable suspension of perovskite NCs on graphene,the mixtures were placed in an ultrasonic bath for 1 h. The presenceof defects and surface oxygenated functional groups in the grapheneprobably promotes noncovalent interactions  with the perovskite NCs.After thelead-free perovskite synthesis, commercially availablegraphene nanoplatelets  were dispersed inisopropanol (0.3 mg/mL). Then, graphene was exfoliated by applyinga pulsed sonication (1 s on/2 s off) at 280 W for 90 min on an ultrasonictip. Afterward, Cs3 of volume), which is connected to a gas mixing and deliverysystem. A pure dry air atmosphere (Air Premier purity: 99.999%) andcalibrated gas cylinders containing the target gas diluted in dryair were utilized in the sensing measurements. Additionally, the effectof the ambient moisture was also studied, and for this reason, a controllerevaporator mixer  was usedto humidify the atmosphere.The resultinggraphene was loaded with the different lead-free perovskite NCs depositedby a spray coating technique and employing pure nitrogen as a carriergas. Specifically, the hybrid nanomaterials were deposited onto interdigitatedelectrodes (IDE) already screen-printed in alumina substrates. Thesensing devices were placed in an airtight Teflon chamber  usinga set of mass-flow controllers and electronic valves. The gas sensors were stabilized for 15 minunder dry air before each exposition to a specific concentration ofthe target gas for 5 min. Indeed, successive and increasing concentrationswere applied by performing their dilution with dry air. Then, sensorresponses were defined as Δ3Cu2Br5 and Cs2AgBiBr6 NCs, respectively. The identified XRD patterns were compared withthose previously reported,19 revealing a good match and confirmingthe orthorhombic and the cubic phase for the Cs3Cu2Br5 and Cs2AgBiBr6, respectively.The X-ray diffraction (XRD)patterns of the perovskite NCs were recorded on a Philips X’PERTdiffractometer that was equipped with a proportional detector anda secondary graphite monochromator. The data were collected stepwiseover the range 2θ = 2–20° at steps of 0.02°at an accumulation time of 20 s/step and using the Cu Kα radiation(λ = 1.54178 Å). 3Cu2Br5 and Cs2AgBiBr6, respectively.Likewise, interplanar distances of 2.03 and 3.5 Å were registeredfor Cs3Cu2Br5 and Cs2AgBiBr6, respectively. These similar parameters and high crystallinityobserved for both types of nanocrystals would enable a reliable comparisonof the sensing performance. The nanocrystal size distribution is illustratedin Figure S1, and an image of the baregraphene nanoplatelets is shown in Figure S2. Finally, the resulting nanomaterial, which consists of lead-freeperovskites supported on graphene, was analyzed through a field-effectscanning electron microscope (FESEM). Figure S3a shows a homogeneous layer of the nanohybrid developed. It is worthnoting that the porous surface is of paramount importance for thegas sensing performance.20 The bright spotsin Figure S3b reveal the random nanocrystaldistribution on graphene.High-resolution transmission electron microscope(HRTEM) imageswere recorded using a JEOL JEM 2100F, and the average nanocrystalsize and interplanar distances were obtained through ImageJ and Gatansoftware. 3Cu2Br5 NCs 2 function versus the photon energy , and subsequently, the band-gap energies were estimatedthrough a Tauc plot. With regard to the Cs2Br5 NCs 2a, a welinset in 2a. As a 2AgBiBr6 NCs exhibit an exciton peak at 450 nm  measurements were obtainedusing an Edinburgh Instruments FLS1100 spectrofluorometer and a 450W Xenon lamp light equipped with a double monochromator coupled toa cooled photomultiplier (PMT-980). The optical properties were preliminarilystudied under different atmospheres, such as of argon and oxygen.Additionally, NH2 at parts per billionlevels. Concentrations ranging from 50 to 200 ppb were applied, revealinghigher responses (more than twofold) for the graphene hybrid withCs3Cu2Br5 NCs . As expected for a p-type sensitive layer, theresistance levels of both sensors decreased when exposed to an electron-withdrawinggas such as NO2, owing to the higher density of positivecarriers. Both lead-free perovskite nanocrystals presented an ambipolarbehavior, but the p-type behavior of the film was given by graphene,which is the most abundant material in the hybrid. Defining the sensorsensitivity as the slope of the calibration curves shown in Figure S4a, graphene decorated with Cs3Cu2Br5 perovskites showed about 2 times highersensitivity than graphene loaded with Cs2AgBiBr6  obtainedfrom the calibration curve. As a result, the Cs3Cu2Br5 supported on graphene shows an LOD and LOQof 8.5 and 28.2 ppb, respectively  defines the 1 h daily maximumNO2 concentration and the annual mean as 100 and 53 ppb,respectively.24 Similarly, the air qualitystandards defined by the European Commission establish 106 and 21ppb as the maximum exposure for an average period of 1 h and a year,respectively.25 Despite the lower sensitivityof Cs2AgBiBr6, this nanomaterial shows an LODand LOQ of 26.3 and 87.8 ppb, respectively .Considering the experimental results obtained, these limits were estimatedthrough the following equations:ectively 1. These ectively 1. It is 2 induce health problems such as eye irritation and irregulationsin the respiratory system  and cardiovascular system such as tachycardia.26 Therefore, considering that the National Institutefor Occupational Safety and Health (NIOSH) established 1 ppm of NO227 as the recommended exposurelimit (REL), several measurements were carried out at this concentrationrange. Increasing NO2 levels from 250 ppb to 1 ppm weretested , revealing repeatableresponses and better sensing performance for the Cs3Cu2Br5 NCs supported on graphene . As expected, significant sensing responses wereobtained when detecting NO2, owing to the large chargetransfer between this gas with both graphene and lead-free perovskites.29 NO2 has a lone-pair electron, and when it is adsorbed,the bond distance is usually short, resulting in a relatively largecharge transfer in comparison to gases of a different nature. It isworth noting that the bare graphene was also tested for detectingNO2 at this concentration range. However, Figure S5a demonstrates that their resistance changes aresignificantly lower in comparison to the graphene loaded with NCs.Additionally, Figure S5b shows that baregraphene presents a lower sensitivity (up to fivefold) than that ofthe nanocomposites developed. Therefore, considering the limited sensingperformance of the bare graphene sensor, the use for detecting lowerNO2 levels and other gases that induce lower responsesis not shown.Not limited to this, acute exposure to higher concentrations ofNO2 in the 250–1000 ppm range. Specifically, four different hydrogenconcentrations were applied, revealing repeatable responses. However,calibration curves depicted in Figure S4b show that Cs3Cu2Br5 presents higherresponses and sensitivity (up to threefold) than those of Cs2AgBiBr6 NCs, resulting in lower detection and quantificationlimits were applied , or in other words,increasing concentrations of NH3 induce negligible increasesin the resistance changes. These results constitute an important barrierfor employing the Cs2AgBiBr6 NCs for detectingthis gas in ambient monitoring applications. Conversely, Cs3Cu2Br5 perovskites present clearer responsesfor the different NH3 levels and higher stability, resultingin higher sensitivity (17-fold than the Cs2AgBiBr6 NCs) and lower detection and quantification limits  was measured for thefirst time using lead-free perovskites. In particular, four differentconcentrations  were applied during consecutivecycles  defined by the NIOSH.33 The Cs2AgBiBr6 NCs supportedon graphene have not been constituted as an alternative for detectingthis gas compound since extremely low resistance changes and a continuousbaseline drift  can be observed.In contrast, the Cs3Cu2Br5 perovskitesdemonstrated suitable H2S detection. Surprisingly, thesensitivity of Cs3Cu2Br5 is approximately360 times higher than that of Cs2AgBiBr6 ,decreasing their resistance levels when exposed to H2S.The reason for this change is still controversial, but the exothermicadsorption of H2S might be a plausible explanation. Consideringthe excellent response of Cs3Cu2Br5 toward H2S, this exceptional interaction would inducean intense exothermic process. Indeed, DFT calculations demonstratedthat doped carbon-based nanomaterials can shift from a p-type to ann-type behavior because of the Seebeck effect when H2Sis detected.34 This phenomenon might occurwhen an intense exothermic reaction through the H2S adsorptioncreates a temperature gradient in the sensitive layer that is convertedinto a thermoelectric effect.Finally, hydrogensulfide , probably because of the slight resistancebaseline drift over time. The reason is that the interaction withH2S is partially irreversible due to the strongly reducingproperties of this gas. In addition, the exothermic adsorption ofH2S is translated into a thermoelectric effect that isprobably lowering the repeatability of the sensing responses.It is worth mentioning that Cs2 levels),the H2S is more associated with leakage events. Additionally,considering that PEL exposure is defined as 50 ppm of H2S for 10 min, their detection and sensor reversibility were studiedby applying those conditions . The clear and fast response registered is worth noting, and despitethe sensor recovery process needing a few hours, the reversibilitytoward H2S is almost completed.As a result, progressive desensitization is observed after eachcycle of four concentrations. Nevertheless, unlike gases for ambientmonitoring purposes  environment by applying consecutivepulses of 200 ppb . Both typesof lead-free perovskites can effectively detect NO2 inboth atmospheric conditions and with outstanding repeatability. Thisfact demonstrates the high stability of the inorganic perovskitesutilized toward the relative humidity. However, interestingly, as 3Cu2Br5 NCs, while it increases that of Cs2AgBiBr6. The sensing mechanism involving lead-freeperovskites in a humid environment is still controversial, but recently,it was reported that Cs3Cu2Br5 isnot intensively affected at such relative humidity levels.35 In this perspective, water molecules can passivatethe Cs3Cu2Br5 NCs since their interactionis competitive with NO2. When H2O moleculesinteract with this perovskite, a smaller charge transfer would occurin comparison to the target gas, resulting in a slightly lower responseto NO2. Conversely, Cs2AgBiBr6 hasbeen demonstrated to show high reactivity and excellent charge transferwhen interacting with H2O molecules,36 which probably enhances the response in a humid environment.At 40% of relative humidity, chemisorption of water can be expectedat the Cs2AgBiBr6, which does not compromisethe charge transfer.37 However, at higherhumidity levels, physisorption can be also expected over the chemisorbedwater molecules, creating a sort of humidity layer over the sensitivefilm and inducing a proton hopping.37 Tobetter apprehend the high potential of lead-free perovskite nanocrystals,additional sensing parameters were studied using the developed nanocomposites.The sensor repeatability (2 exposures (500 ppb) for 15 min and between them, recovery stepsof 30 min using pure synthetic air. The Cu-based perovskite NCs supportedon graphene have demonstrated outstanding air stability over time38 as well as noteworthy repeatability (relativeerror of 3.1%).Furthermore, thepresence of ambient moisture when detecting gascompounds plays an essential role in the sensor instability or cross-interference.In this perspective, the NO 200 ppb S7. Both  200 ppb S7. Both 7H8) and carbon dioxide (CO2) weremeasured. 3Cu2Br5 shows a higher signal than Cs2AgBiBr6 forall the gas compounds tested. On the other hand, considering the resistancechanges with the concentration applied for each target gas, the NO2 detection stands out due to the higher sensing response obtaineddespite the lower concentration tested. In consequence, the Cs3Cu2Br5 NCs supported on graphene area promising option for monitoring the NO2 levels in theatmosphere. Nonetheless, it is also worth highlighting the sensitiveand reversible detection of H2S, being an alternative fordetecting leakage events of this harmful gas compound.Nevertheless, cross-sensitivity can be a significantdrawback thatcan prevent the implementation of the developed nanocomposites incommercial devices. In this regard, additional gases such as toluene that experiences amutual attraction to form a neutral quasiparticle. Thus, the excitonbinding energy would possess a key role in sensing performance. Whenlead-free perovskites are employed to grow thin films and are operatedon at room temperature, the exciton binding energy is smaller thanthe thermal energy.40 As a result, freecarriers are generated but without transporting a net electric charge.41 Conversely, the present work reported the useof nanocrystals, which are confined structures that increase the excitonbinding energy above the thermal energy under room-temperature operations.As a result of this confinement effect, the perovskite nanocrystalstend to promote the radiative recombination of carriers and suppressthe exciton dissociation.42 In addition,perovskite nanocrystals can easily form self-trapped excitons thatfurther promote the interaction with gas compounds.43 For that reason, supporting lead-free perovskite nanocrystalson graphene seems to be a suitable alternative for developing semiconducting-sensitivelayers. In the first step, nanocrystals would intensively interactwith the target gases. Additionally, if the perovskites are supportedon graphene, it is possible to take advantage of the high and efficientcarrier mobility of the graphene.To date, the few works thatreported the use of lead-free perovskites as gas sensors mostly employedthem as bulky thin films at room temperature.44 At the nanoscale, this property has special importance owing tothe relatively high surface-to-volume ratio of the defects.45 Perovskites have been mostly used in opticalapplications in which defects are an adverse parameter that shouldbe removed to the maximum extent. In contrast, the defects presentin perovskites can be beneficial in semiconducting applications tosome point because defects can serve as electronic traps, inducinga higher interaction with gas compounds. Additionally, lead-free perovskitespossess worse optical properties than lead-based perovskites owingto their larger density of defects.40 However,once again, this high concentration of defects in lead-free perovskitesis probably beneficial from the gas sensing point of view as observedin this work in comparison to lead-based perovskites.9 In this perspective, the perovskite defects, dangling bonds,and even the presence of organic ligands can form trap states46 that tend to increase the interaction with thetarget gases. This probably explains the excellent properties of perovskiteNCs when employed in gas-sensing devices. It is also worth mentioningthat, in perovskite nanocrystals, the CB consists of spin–orbitcoupling, while the VB has an antibonding nature. These contrastingdifferences in the orbital characteristics induce the formation ofshallow trap states,47 which probably furtherincreases the sensitivity to the target gases.It is also worth noting thedefect tolerance of halide perovskites, which is correlated to thelack of bonding–antibonding interactions between the valenceband (VB) and the conduction band (CB).48 Therefore, for the same exposure time to target gases,higher resistance changes can be expected for a direct band gap, especiallyif the exposure time is short enough for not achieving the responsesaturation. This is crucial for ambient monitoring purposes becausethe pollutant levels usually are fluctuating over time. Thus, a sensorsaturation operated at room temperature toward a specific gas usuallyrequires a high concentration for a relatively long-term period. Thisfact is probably one of the reasons explaining the better sensingperformance of Cs3Cu2Br5 than Cs2AgBiBr6  toward a wide variety of pollutants. Thisagrees with the experimental findings shown in the present work , it has also been demonstrated that the strengthof exciton–phonon coupling in direct band-gap NCs is moderate,favoring the radiative self-trapped excitons. In contrast, indirectband gaps can show a strong carrier–phonon coupling effect,resulting in more effective non-radiative self-trapped states. Thisagain suggests the importance of the type of semiconductor and thestrength of exciton–photon coupling in the sensing mechanism.Therefore, the direct and indirect band gap also influences the propertiesof the free exciton, the strength of exciton–phonon coupling,and the radiative or non-radiative nature of self-trapped excitons,determining the degree of interaction with the gas molecules.53 In this regard, to give some insight into theproposed process, the changes in the photoluminescence (PL) of thesupported NCs under different gases were studied. Although these experimentsstill require further study, it is clearly observed that the magnitudeof the PL changes under different gases. This change is much largerin the case of Cs3Cu2Br5 than Cs2AgBiBr6 .These results support the importance of the strength of the exciton–phononcoupling in the sensing mechanism.Another reason related to the band-gap narrowingof perovskitenanocrystals is the presence of self-trapped excitons when gas compoundsinteract with the lead-free perovskites inducing excited-state transitions,consisting of recombinations of free excitons whose emission energyis much smaller than the band gap. In other words, when the electronsare excited, they leave the ground state, inducing the formation ofholes in that ground state. Afterward, electrons and holes radiativelyrecombine in pairs.and gaps6a. The dNevertheless, the comprehensive sensing mechanismsin lead-freeperovskite nanocrystals supported on graphene involve both nanomaterials.In this regard, despite the fact that a direct interaction of graphenewith the gas compounds cannot be ruled out, considering the low sensitivityof bare graphene, the charge transfer is probably negligible in comparisonto the nanocrystals. In other words, a limited interaction and smallcharge transfer can be expected between the target gases and the oxygen-containingfunctional groups grafted at the graphene surface. However, the presenceof lead-free perovskite nanocrystals has a crucial role in enhancingthe sensing performance, increasing the sensitivity, and loweringthe detection and quantification limits. In the nanohybrids developed,graphene would act as a transducing element owing to its excellentcarrier transport. For that reason, while perovskite nanocrystalsare ambipolar charge carriers, the sensitive film usually acts asa p-type semiconductor because graphene is the dominant carrier transportnanomaterial.2 interactswith the NCs, the electron–hole pairs are separated and canbe moved toward energy landscapes across the band gap. The interactionof an electron-withdrawing gas with the perovskites induces an accumulationof positive charge carriers at the nanocrystals (3) interacts with the lead-free perovskites, negative carriers areaccumulated at the nanocrystal  probablyhas lower energy barriers than Cs2AgBiBr6 (indirectbandgap) with respect of graphene energy levels. This can be translatedinto a more efficient extraction of charge carriers of Cs3Cu2Br5 NCs and, in consequence, higher sensingresponses.In this perspective, when detecting oxidizinggas compounds , the resistivity of the film decreases owingto the higher density of positive carriers (holes) in graphene, whichis the transducing element. For instance, when NOcrystals 6a. Then,ocrystal 6b. ThereEnvironmentally friendly and nontoxic nanomaterialssuch as lead-freehalide perovskite nanocrystals were supported on graphene for detectinga wide variety of harmful gases at trace levels. In addition, thenanomaterials employed for developing the gas sensors are quite abundantand inexpensive, paving the way toward a straightforward and mass-scalablesynthesis. Four different gases were effectively detected in a fewminutes and at concentrations below the threshold limit values, revealinglimits of detection and quantification low enough for ambient monitoringapplications. In addition, remarkable stability and repeatabilitywere achieved under room-temperature conditions, which paves the wayfor achieving low-power consumption devices.2 and H2Swere detected using lead-free perovskites for the first time, andthe ultrasensitive detection of NO2 was achieved at partsper billion levels. To increase our knowledge, the intrinsic propertiesof the nanocrystals were studied for unraveling the sensing mechanismsand correlating them with significant differences observed in thesensing performance. Overall, the Cs3Cu2Br5 NCs present higher sensitivity towards gase than the Cs2AgBiBr6 NCs, showing lower LOD and LOQ values forall the gases tested. Two main reasons can probably explain theseexperimental findings. On the one hand, the UV–vis absorptionrevealed that Cs3Cu2Br5 presentsa direct band gap, which is favorable from the gas sensing point ofview. Conversely, the Cs2AgBiBr6 NCs showedan indirect band gap. On the other hand, the strength of exciton–phononcoupling of self-trapped excitons in both types of perovskites NCsplays an important role, being stronger in the case of Cs2AgBiBr6 NCs with an indirect band gap, limiting the efficientgeneration of separate charges and reducing the interaction with gasmolecules.The present workreports for the first time the development ofa hybrid comprising graphene and lead-free perovskite nanocrystals.Additionally, some gases such as H3Cu2Br5 NCs usually presentoutstanding stability in comparison to organic–inorganic hybridperovskites. The reason is that organic cations such as formamidiniumor methylammonium are susceptible to degradation or decompositionunder standard environmental conditions or when exposed to specificgas compounds. Additionally, considering the same experimental conditionsand 5 min of gas exposure to NO2, the Cs2AgBiBr6 NCs supported on graphene show significantly better sensingperformance than more harmful alternatives such as lead halide perovskites.For instance, the Cs2AgBiBr6 NCs present highersensitivity  than lead-based NCs such as CH3NH3PbBr310 whenboth are supported on graphene. This is probably because lead-freeperovskites possess a defect tolerance and a high density of surfacedefects that are acting as electronic traps. These defects are probablya drawback in optical applications, but from the gas sensing pointof view, since defects act as electronic traps for interacting withgas compounds, their presence is an opportunity for developing highlysensitive nanomaterials. Not limited to this, a wide variety of lead-freeperovskite compositions can be developed, paving the way toward theexploitation of multiple configurations for selectively detectingthe target gases.It is worth highlighting that all-inorganic-basedperovskites suchas the Cs


This is caused by an increase in the conductivity of PEDOT:PSS due to the interaction with ethylene glycol and synergetic effect on the composite properties of h-BN:graphene films. The addition of PEDOT:PSS to the h-BN:graphene composite leads to the correction of the bonds between nanoparticles and a weak change in the resistance under the tensile strain caused by the sample bending. A more pronounced flexibility of the composite films with tree components is demonstrated. The self-organization effects for graphene flakes and polar h-BN flakes lead to the formation of micrometer sized plates in drops and uniform-in-size nanoparticles in inks. The ratio of the components in the composite was found for the observed strong hysteresis and a negative differential resistance. Generally, PEDOT:PSS and ethylene glycol composite films are promising for their application as electrodes or active elements for logic and signal processing.The structure and electric properties of hexagonal boron nitride (h-BN):graphene composite with additives of the conductive polymer PEDOT:PSS and ethylene glycol were examined. The graphene and h-BN flakes synthesized in plasma with nanometer sizes were used for experiments. It was found that the addition of more than 10 The composite materials are formed by mingling at least two or more materials having different properties, resulting in the unique output characteristics of the composite material ,2. AdditThe strategies of composite synthesis, characterization techniques and the mechanism of interaction between components are thoroughly discussed and examined since they are pivotal to understanding the properties of the composites . The possibility to combine different 2D materials in one layer allows one to additionally manage the electron and optical properties of the resulting composite. The widely used method of mechanical transfer of individual 2D crystals provides the quality of fabricated heterostructures and interfaces, but it is not scalable ,9,10. ThAt present, h-BN:graphene composites are widely studied to control the thermal conductivity of the composite material ,18. The An increase in graphene synthesis temperature leads to improving its quality. In our studies, we used materials synthesized under extreme plasma conditions. Plasma methods make it possible to control the synthesis process and control the geometry of the synthesis products . In the To synthesize graphene, we applied the plasma-chemical approach based on a 40 kW DC plasma torch with the expanding output electrode channel and the plasma jet vortex stabilization . The des3. As shown in [The product of the plasma–chemical synthesis is graphene powder  with a typical bulk density of 0.1 mg/cmshown in , the synshown in ,21,22. Tshown in ,23,24). We synthesized the graphene-like structure of hexagonal boron nitride in a plasma chemical reactor with a DC plasma torch. The stable operation of the used plasma torch is ensured by using inert helium as a plasma-forming gas in the pressure range of 500–700 Torr to the atmospheric pressure. Therefore, we used helium both for the synthesis of graphene and for producing boron nitride particles. A series of experiments established that nanosized boron nitride particles , first-order C-C scattering G (1579 cm−1) and second-order band 2D (2692 cm−1) [The AFM images and Raman spectra for h-BN and graphene flakes are given in −1 ) and gra92 cm−1) ,26. The 92 cm−1) . The ratThe composite suspension was created from the graphene suspension of 2 mg/mL and BN suspension of 2 mg/mL and then by varying the BN:G suspension content in the range 1:1 to 1:20. The liquid component of all suspensions consists of ethanol (70%) and water (30%). The stirring of suspensions with the use of a shaker leads to the formation of a homogeneous solution.The conductive polymer PEDOT:PSS  was also used for the creation of the composite with graphene. The films created from PEDOT:PSS by thick drops ~1 μm have a resistance of about 6–10 kΩ/sq. For the creation of ink, more additives were created. First of all, there was ethylene glycol  with ~3−4–10−2 mass%). The scattering in resistance values in −4 mass% of PEDOT:PSS for G-1 and at the 2 × 10−3 mass% for G-2. Thus, for small graphene flakes, one needs a higher content of PEDOT:PSS to decrease the composite resistance. The additive of the ethylene glycol leads to a strong decrease in the composite resistance. It is well known that PEDOT, which is insoluble in most solvents, can be dispersed in water by using poly(styrene sulfonate) (PSS) as a counter ion, which also serves as an excellent oxidizing agent and charge compensator [The effect of PEDOT:PSS polymer addition and PEDOT:PSS plus ethylene glycol on the graphene film resistance is presented in pensator ,30. On tpensator ,32. The The films and particles formed in different composites due to the self-organization process are demonstrated in −3 mass%. In all cases, the graphene content was higher than the percolation threshold for 2D materials . The fiThe resistances of the h-BN:G:PEDOT:PSS composite films with G-1 are decreased by four to five orders of magnitudes down to 60–70 or 20 Ohm/sq. In the case of G-2, the resistance is decreased down to values of 20–35 Ohm/sq.One current-voltage characteristic of the BN:G:PEDOT:PSS composite films with BN:G ratio 1:1 is shown in Formation of the composite particles for 2D printing is based on using ultrasonic treatment to limit the clustering process discussed above. This combination leads to the formation of relatively small composite particles. Moreover, the ink composite is more complicated. Ethylene glycol provides the stabilization of the inks and prevents the further clustering. Nevertheless, after the first fast stage of clustering, the second slow stage also occurs. The typical time of this second stage is ~10 days when weak connected clusters of composite particles are formed and the repeated ultrasonic treatment in combination with ink filtration using track membranes before printing allows ones to restore the individual particles in the inks.−3 mass%) with the addition of ethylene glycol (30 vol.%) for h-BN:G relation 1:1. We made the structures with two types of layers using 30 and 60 printed passes. The thickness of the layers for G-1 and G-2 in the case of 30 passes was 220–250 nm and 160–200 nm, respectively. First of all, it is worth mentioning that, despite the different sizes of the pristine graphene flakes G-1 and G-2 used to create composites, composite particles are found to be very similar in shape and slightly larger for G-1. It is suggested that PEDOT:PSS take part in the connection of the particles; it can be directly observed between the particles in the top-left part of In The sheet resistances of the printed layer measured with the use of the four-probe equipment are given in Testing the composite film flexibility was made on dropped and printed layers with the use of bending (tensile strain). The strain value ε was estimated from equation ε = (d + t)/2r, where d is the PET substrate thickness, t is the film thickness and r is the bending radius. −3 mass% we created a more flexible material based on the h-BN:G composite.The data given in Movies about the h-BN suspension, graphene suspension and its composites drying can be found in the Concerning comparison with known composite systems, it worth mentioning that observation of either non-linear I-V characteristics with the negative differential resistance, or memristive swithings, is typical for different composite films and structures ,34,35. T2 significantly enlarged (30%) the critical load of the G/SiO2 interface failure, compared to that of the graphene monolayer [The interlayer adhesion in the graphene/h-BN multilayered films is of significant importance for their structural and electric properties. It was found that the h-BN/G bilayer deposited on SiOonolayer . On the onolayer  predicteonolayer  observedonolayer . These fTo study the morphology and local properties with a high spatial resolution, we employed Atomic Force Microscopy (AFM) and Raman spectroscopy. The Raman spectra were recorded on a Horiba Jobin Yvon T64000 spectrometer with a 1024-pixel LN/CCD detector and an Ar+ 514.5 nm laser under ambient conditions. A Solver PRO NT-MDT scanning microscope was employed for taking AFM images from the surface of the examined films or individual nanoparticles and for evaluating the sample thicknesses. The measurements were carried out in contact and semicontact modes. The surface morphology of the created films was also studied using a JEOL JSM-7800F  scanning electron microscope (SEM). Then we studied the layer resistance of the fabricated films using four-probe JANDEL equipment and the HM21 Test Unit at room temperature . The current-voltage characteristics were also measured with a Keithley picoamperemeter (model 6485) on the samples furnished with two contacts prepared from the silver alloy.−1.In the fabrication of crossbar structures, the suspensions were applied onto a PET substrate using a Dimatix FUJIFILM DMP-2831 jet printer. Silver contacts were printed with 5-nm particles. After printing five layers, an Ag line 400 nm thick at its centerline was obtained. The sheet resistance was 2.5–3 Ohm sq−3 mass% of PEDOT:PSS, in combination with ethylene glycol (20–30% of inks for the 2D printing technology), to the graphene suspension or h-BN:graphene structure leads to a strong decrease (four to five orders of magnitude in our case) in the resistance of the films created from these suspensions. This is caused by an increase in the PEDOT:PSS conductivity and its synergetic interaction with graphene and h-BN. On the other hand, the self-organization effects for graphene flakes and polar h-BN nanoparticles were revealed, and that leads to the formation of few-micrometer composite plates in the drops and uniform size of the composite nanoparticles in inks and printed layers. Moreover, using small graphene G-2 leads to stronger self-organization effects. One more attractive property of the composite used is the fact that the addition of the PEDOT:PSS to the h-BN:graphene composite leads to the correction of the bonds between nanoparticles and a weak change of the resistance change under the tensile strain caused by bending. Composite films h-BN:graphene:PEDOT:PSS become flexible despite the presence of h-BN flakes.The structure, flexibility and electric properties of h-BN:graphene films, with the additives of conductive polymer PEDOT:PSS and ethylene glycol, were examined. The graphene and h-BN flakes synthesized in plasma with nanometer sizes were used for the creation of composites with different contents. It was found that the addition of more than 10


The epidemiology of recurrent bacterial bloodstream infections (rBSI) has not been fully characterized. Evaluating rBSI represents opportunities to inform morbidity risk factors and prevention strategies. We describe the clinical and microbiological features of rBSI in the US Military Health System (MHS) in a prospective cohort study, including retired and active-duty US uniformed service members and their beneficiaries.We collected data for rBSI episodes from MHS beneficiaries (Jan 2010 – Dec 2019). A rBSI is defined as growth of the same bacterial pathogen in blood culture >14 days after the index or previous episode. Demographics and comorbidities were collected prior to the index BSI. Microbiological data were obtained from the Navy and Marine Corps Public Health Center. Descriptive statistics are presented.Escherichia coli had the largest proportion among all patients with rBSI (31% of 646); however, Enterococcus spp. accounted for the highest proportion of rBSI within a given pathogen subgroup . Pseudomonas aeruginosa BSI had the shortest average time to recurrence (119 days), and Acinetobacter spp. had the highest frequency of BSI recurrences per patient (mean of 3). Male sex (59.9%) and age ≥65 years (52.9%) were most common among the rBSI patients. The updated Charlson Comorbidity index score preceding the index BSI was a median of 5.0, and chronic pulmonary disease (57.3%) and diabetes (56.6%) contributed the largest proportion of common comorbidities. A total of 88 (13%) rBSI patients had their index BSI while hospitalized following trauma where S. aureus was the most common (37.5%) bacterial pathogen.A total of 12,749 beneficiaries were diagnosed with a BSI attributed to 1 of the 15 most common bacterial pathogens associated with BSI in the MHS, with 646 (5.1%) experiencing a rBSI. Overall, the proportion of rBSI (5.1%) in our cohort of MHS beneficiaries was generally lower than that previously reported in the literature. Individuals with rBSI had a substantial burden of comorbid disease with 13% having trauma precede the index BSI. Identifying risk factors for recurrence may improve management strategies of primary BSI and may reduce morbidity of subsequent BSI.John H. Powers, III, MD, Arrevus: Advisor/Consultant|Eicos: Advisor/Consultant|Evofem: Advisor/Consultant|Eyecheck: Advisor/Consultant|Gilead: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|OPKO: Advisor/Consultant|Resolve: Advisor/Consultant|Romark: Advisor/Consultant|SpineBioPharma: Advisor/Consultant|UTIlity: Advisor/Consultant|Vir: Advisor/Consultant.


Carbon nanomaterials have received increased attention in the last few years due to their potential applications in several areas. In medicine, for example, these nanomaterials could be used as contrast agents, drug transporters, and tissue regenerators or in gene therapy. This makes it necessary to know the behavior of carbon nanomaterials in biological media to assure good fluidity and the absence of deleterious effects on human health. In this work, the rheological characterization of different graphene nanomaterials in fetal bovine serum and other fluids, such as bovine serum albumin and water, is studied using rotational and microfluidic chip rheometry. Graphene oxide, graphene nanoplatelets, and expanded graphene oxide at concentrations between 1 and 3 mg/mL and temperatures in the 25–40 °C range were used. The suspensions were also characterized by transmission and scanning electron microscopy and atomic force microscopy, and the results show a high tendency to aggregation and reveals that there is a protein–nanomaterial interaction. Although rotational rheometry is customarily used, it cannot provide reliable measurements in low viscosity samples, showing an apparent shear thickening, whereas capillary viscometers need transparent samples; therefore, microfluidic technology appears to be a suitable method to measure low viscosity, non-transparent Newtonian fluids, as it is able to determine small variations in viscosity. No significant changes in viscosity are found within the solid concentration range studied but it decreases between 1.1 and 0.6 mPa·s when the temperature raises from 25 to 40 °C. Novoselov et al., is a two-dimensional carbon sheet comprised of sptructure . This ma2/g, which have great interest due to their excellent electrical conductivity and high mechanical properties [Graphene-based materials, such as graphene oxide (GO) or graphene nanoplatelets (GNP), maintain many of the magnificent and interesting properties of graphene. The oxidized form of graphene, GO, contains several reactive oxygen functional groups on the surface that enhance its dispersion and stability in aqueous and organic solvents . GO is poperties ,8.Graphenes are used in a broad variety of applications, including quantum physics, nanoelectronics, catalysis, nanocomposites, and sensor technology ,10. It hThe physical adsorption of proteins onto the surface of graphene oxide is achieved through non-covalent interactions. The interactions involved in protein–GO/rGO complex formation are electrostatic interactions, hydrogen bonding, hydrophobic interactions, van der Waals forces, and π–π stacking interactions. The non-specific interactions are mainly controlled by the layer content and interfacial stress transfer between the graphene oxide layers and the protein structure. 2 group on BSA chains, together with some hydrogen bonding [Bovine serum albumin (BSA) is commonly used as a model protein due to its high percentage of sequence identities compared to human serum albumin , low cost and high structural stability . BSA is  bonding . The BSA bonding , who sho bonding . Fetal b bonding .−1. In contrast, when the dispersion medium is FBS, the viscosity range of MWCNTs is narrower, between 1.8 and 2.8 mPa·s. The same happens when comparing with the values obtained for the SWCNTs. However, to the best of our knowledge, no studies on the rheological behavior of graphene-related materials in biological media have been reported in the literature. Considering all the above, in this work, a structural and rheological characterization of the interaction of three nanomaterials based on graphene, i.e., graphene oxide (GO), graphene nanoplatelets (GNP) and expanded graphene oxide (EGO) with two different biological media, BSA and FBS, has been performed. Some works have evaluated the rheological properties of the protein solutions ,27,28, b2/g and median mesoporous pore diameter of 12.8 nm. GNPs have a degree of oxidation of 2%, a surface area of 101 m2/g, a density of 2 g/cm3 and lateral dimension of about 2–3 micron with less than 5 layers thick. Expanded graphene oxide (EGO) was obtained from the Chemical Engineering Laboratory of the University of Castilla La Mancha, Ciudad Real, Spain. It was synthesized following the procedure described elsewhere [2/g and median mesoporous pore diameter of 22 nm. Biological fluids, bovine fetal serum  and bovine serum albumin  were obtained from Gibco  and Sigma Aldrich, Saint Louis, MO, USA, respectively.Graphene oxide (GO) and graphene nanoplatelets (GNP) (NIT GRAPHENIT-OX) were obtained from Nanoinnova Technologies S.L, Illescas, Spain. GO has a specific surface area of 20–35 mlsewhere  based onlsewhere . EGO hasDispersions of the three graphenoids were prepared  in biolo−4 mg/mL were deposited onto a cleaved muscovite mica substrate and left drying in air for subsequent AFM measurement. Tapping-mode topographic AFM was used.In a previous paper, Cerpa et al. performed the characterization of powders GO and EGO using different techniques  . In this−1 in 300 s, a plateau at 1000 s−1 for 60 s and a further decrease to 0 shear rate in 300 s. Measurements were made for different concentrations of GO, GNP and EGO suspensions (1–3 mg/mL) at temperatures of 25, 30, 37 and 40 ± 0.1 °C, using FBS as dispersing medium and were repeated successively to obtain consistent values. In addition, measurements were made for each nanomaterial dispersed in water and BSA at 1 mg/mL to determine the influence of the dispersion medium on the viscosity values. Due to the limitations of rotational rheometry for low viscosities, the rheological measurements at high shear rates were performed in a rheometer with micrometric capillaries on a chip FluidicamRheo  at different temperatures in the 25–40 °C range. These measurements are based on the concurrent flow of the sample and a reference liquid of similar viscosity through a Y-shaped tube with a diameter size of 150 μm, thus, allowing the determination of viscosities in the shear rate range from 1000 to near 20,000 s−1. Zeta potential measurements were performed with a Zetasizer Nano ZS  instrument at neutral pH values (6.6 to 7.0), using KCl 0.1 M as inert electrolyte. A pH meter HI5221  was used to control the pH of the dispersions. The rheological measurements were performed in a Haake RheoStress 6000 rotational rheometer , equipped with a double-cone and plate system (2° cone angle and 60 mm in diameter). A three-stage measuring program was used, with a linear increase in shear rate from 0 to 1000 sStructural characterization was carried out using microscopy techniques to determine the shape and size of the nanopowders, as well as the possible morphological changes and interactions between the protein of fetal bovine serum and the carbon nanostructures. A more detailed analysis of the particles’ morphology was performed by SEM. The 2D and 3D AFM images of the three graphene-based nanomaterials and their respective morphologies after interacting with the FBS are displayed in Zeta potential measurements allow a quantitative determination of the stability of powders in suspension. Zeta potentials are calculated from the electrophoretic mobility values obtained after three different measurements for each sample. The average of these three measurements with their respective standard deviation are shown in The influence of different variables, such as kind of nanomaterial, concentration, temperature, and type of fluid on the rheological properties of the formed dispersions is discussed below.The influence of the different graphene-based nanomaterial on the viscosity in presence of the biologic fluid and fetal bovine serum is shown in The FBS curve shows a slightly higher viscosity value than that of EGO + FBS. This may be associated with the use of sonication in the last case, which decreases the intermolecular adhesion forces between EGO and FBS and contributes to particle dispersion. In general, the use of sonication for low content suspensions leads to a better dispersion of the solid phase into the liquid and this is expected to occur in all the studied samples. In fact, this happens for EGO dispersed in FBS and confirms the effect of stabilization observed in the zeta potential values. However, in the case of the dispersion of GO in FBS, the viscosity increases. This could be attributed to a deficient dispersion, but zeta potential measurements demonstrated that the values were the same for GO and EGO, so an external factor should be responsible for this viscosity increase. Since there are no other external parameters, this could be explained by considering that there is an interaction of GO particles with albumin molecules that can promote some agglomeration. Another aspect is that under sonication, the creation of a protein-corona is favoured, as suggested by Raslan et al. . −1. The curves of viscosity obtained for four different concentration dispersions are plotted in The influence of the nanomaterial concentration on the viscosity was studied by keeping the temperature constant at 37 °C and the shear rate at 200 s−1) to avoid the apparent shear thickening effect associated with wall slippage. In order to understand the behaviour of the dispersions of nanomaterials in other biological fluids different from FBS, the study was complemented with a few measurements of viscosity in other fluids, such as bovine serum albumin and water. The viscosity of GO, GNP and EGO dispersed in the 3 considered fluids  at 1 mg/mL of concentration was measured using the rotational rheometer and values were taken at relatively low shear rates (200 sThe effect of temperature on the viscosity of GO, GNP and EGO dispersed in FBS at a concentration of 1 mg/mL is shown in −1 and measured in the Fluidicam between 1000 and 10,000 s−1. The flow curves obtained at a high shear rate show a small increase in the viscosity, as observed in −1. According to these results, the viscosity values for the GO + FBS, GNP + FBS and EGO + FBS dispersions are between 1.1 and 0.6 mPa·s in the temperature range of 25–40 °C.The viscosity values measured in the rotational rheometer at low shear rates are slightly higher than those obtained using a microfluidic chip at higher shear rates of 1000–10,000 sHowever, viscosity values between 1.8 and 1.0 mPa·s for FBS without nanoparticles were obtained at the same temperature range mentioned above. In addition, the viscosity values at temperature of biological interest of 37 °C are between 0.6 and 0.9 mPa·s for the GO + FBS, 0.7–0.8 mPa·s for GNP + FBS and 0.7 mPa·s for the EGO + FBS dispersions, while the viscosity values for FBS at temperature of 37 °C is 1.4–1.1 mPa·s. It can be observed that the type of graphene-based structure does not cause a significant effect on the viscosity when fetal bovine serum is used as the dispersion medium.−1 [−1 [Rothammer et al. found that viscosity changed between 1.0 and 1.4 mPa·s within a shear rate range of 10 to 90 s−1  for bovi−1 [−1 . Mazzucc−1 [−1 , with thThe measurements obtained with microfluidic technology at higher shear rates (−1. However, the rotational rheometer does not have enough precision for the evaluation of very low viscosities, so the microfluidic chip technique provides a new methodology for the unequivocal determination of such low viscosities. Since the apparent shear thickening occurs at relatively high shear rates where slippage is favoured, in the low shear rate region, the values obtained with both types of rheometers are similar and start to be divergent above 200–300 s−1.In In this work, the rheological behavior of dispersions of three graphenoid nanomaterials in biological fluids has been studied. Variables such as the kind of nanomaterial, its concentration, temperature, and type of fluid have been examined.SEM images show a higher tendency to compaction and aggregation of GO, GNP and EGO when the FBS is used as the dispersion medium. The images obtained by AFM show the change in the surface texture, which indicates the nanomaterial–protein interaction.The dispersions of GO + FBS, GNP + FBS and EGO + FBS present Newtonian behavior in all the studied ranges of concentration, although measurements performed with rotational rheometers give an apparent shear thickening. The microfluidic chip rheometer is a much more reliable technique for these systems.The viscosity values obtained are between 0.6 and 1.3 mPa·s for the concentration range of 1–3 mg/mL at a temperature of 37 °C. These values tend to slightly increase when the concentrations increase, although these changes are not significative.The dispersions of nanomaterials in FBS lead to slightly higher viscosity values than those in BSA and water. The viscosity values obtained for GO, GNP and EGO dispersed in FBS at a temperature of 37 °C and a concentration of 1 mg/mL are between 0.6 and 0.9 mPa·s.The viscosity of the dispersions decreases with the temperature from 1.1 to 0.6 mPa·s in the temperature range of 25–40 °C at 1 mg/mL.In summary, this study provides information on the rheological characterization of graphene-based nanomaterials in biological fluids, which can be used in different biomedical applications.


MGT allows for data collection from responders, followed by data analysis to generate findings into a set of categories. Recently, academic papers have revealed a lack of systematic approaches to conducting research in the sustainable project management field, an increasingly important area of study. The current research employs a method to investigate the sustainability practice in Jordan and the complexities and capabilities of sustainable project management. However, despite previous efforts within sustainable project management, researchers still seek consensus on the methodology for its consideration. Therefore, this study describes a novel step-by-step approach for conducting research to achieve this goal. Sustainable project management is challenging since it tends to be either qualitative or quantitative; hence, the identification of the appropriate research method is a hard task for a researcher. As a result, several research methods are often employed, and MGT is introduced as an effective approach. Indeed, since sustainable project management is an emerging field in Jordan, adopting a new research method should be considered over traditional approaches.  Specifications TableResearch is a systematic process of studying materials to establish facts and devise conclusions Sustainable development is an emerging field that focuses on how we live. Seventeen Sustainable Development Goals (SDGs) have been adopted, which aim to improve life on this planet According to the literature, a qualitative approach has many features that align with this research, including attitude measurements based on opinions, views, and close perceptions. In this case, the research is based on respondents’ opinions, beliefs, and insights used to develop a theory or phenomenon GT is a systematic method developed by Glaser and Strauss, whose first book was published in 1967 and entitled, ‘Discovery of Grounded Theory’ As mentioned, sustainable project management is an emerging field not yet employed in Jordan. Therefore, using the modified version of GT allows us to study previous efforts in the field under investigation, compare them to the existing studies in the country and then visualise where and what issues need to be investigated. This combination of GT and theoretical background is called MGT. In this method, the researcher begins the investigation of the existing theory and builds the study based on that theory In MGT, the theory is continuously developed by generating a series of observations The first step of MGT is open coding, which is defined as ‘the analytical process where the collected data are broken down. This is the first stage of analysing qualitative data’ Continuing the process of analysis, axial and selective coding is needed. In this stage, data are reassembled about the nature of relationships through statements amongst the various categories and subcategories •Outline the categories’ properties and dimensions.•Identify the range of actions associated with phenomena.•Link categories to their subcategories based on their relationships.•Clarify how categories and subcategories can relate to each other.Axial coding involves several basic tasks Once the categories have been generalised and their relationships created, we then move on to form the theories. At this stage, selective coding takes place, which typically occurs in the later phases of a study In this MGT strategy, existing practices were employed to explore the gaps in Jordan's practices and overcome such complexities that hinder the sustainability of project management in Jordan. First, the current study applied existing practices to visualise the thinking and understanding of sustainable project management. However, the available international theories of sustainable project management were remote and abstract; they needed to be generalised for the context of Jordan (the country under study). In addition, the practices needed to be customised in detail. Moreover, the fieldwork investigation in Jordan was built upon the data analysis gained from current sustainable project management approaches compared with Jordan's existing practices.Data collection involves the communication process between the provider (respondents) to the collector (researcher) The data collection technique that is well-suited in dealing with qualitative research is based on face-to-face interactions with participants, semi-structured interviews or documentation sources. MGT, which is suited for qualitative research, requires the identification of the sample of participants who are suitable for the research according to a semi-structured interview. In this case, ‘theoretical sampling’ and ‘snowball sampling’ were employed to decide which respondent was needed for each interview question. Therefore, a preliminary sample was contacted to conduct the first set of interview questions, and the face-to-face interviewees were identified. This task ensures the current interview affects the subsequent interview, steering the researcher in the right direction. According to Johanson and Brooks Gap analysis can be used to compare the current situation with the desired one •Sustainability practices in Jordan•Complexity•CapabilityGap analysis provides theoretical implications and determines the main issues that need to be investigated further. In this study, it explored where major improvements were needed for compliance with the relevant practices of sustainable project management worldwide. Additionally, the delivery environment of projects and sustainability were studied and considered external or internal. Moreover, the capability gaps and weaknesses of the existing practices of the organisation were evaluated. As a result, three sections during the interview questions were covered with respect to the sustainable project management field:•Confirm that the protocol of conducting the interviews would be followed consistently.•Examine where the research methods might be inappropriate, unclear or too complicated for this type of research.•Learn how to deal with the interviewees effectively, including appropriate wording, physical observations and overall interview activity.•Estimate how long the field interviews would take by recording the pilot interviews and assess if the time required is reasonable.•Improve the interview questions based on the feedback.After the gap analysis, we derived several questions that were related to the implications of the analysis results. These questions could not be asked directly without testing their reliability and development. In fact, a pilot study is a testing step of a particular research instrument used to obtain feedback from the respondents In the first stage, semi-structured interviews were employed in the current research for open and axial coding for the different interview groups derived from the gap analysis. The interview questions focused on sustainability practices in Jordan, capability, and complexity. Therefore, the second-stage intensive questions were asked according to theoretical implications from existing theories through gap analysis, preliminary interviews and their implication for the next interviews. The structure of the fixed general questions was derived from the sustainability analysis of the existing practices in Jordan. The gap analysis provided an overall picture to direct the fieldwork, which facilitated the design of the interview questions and testing of the existing theories in the Jordanian context. During the fieldwork in Jordan, the researcher conducted formal interviews. The interviewees were encouraged to speak freely about the topic to obtain in-depth information on the research topic and harness any new ideas not evident from the gap analysis. To reduce bias, the process could not guide the interviewees based on the research goals while allowing them to discuss openly in the field. Each group of questions included three interview steps. Step 1 involved the questions derived from the main issues explored through the gap analysis for further investigation through interviews. These issues drove the data collection using categories that emerged from the fieldwork and practical information that could later be collected from the in-depth interviews. This step allowed the interviewees to give opinions and judgements during the fieldwork, yielding valuable information for further investigation into the existing practices of sustainability.Step 2 is an in-depth investigation of the issues mentioned by the interviewees that did not emerge during the gap analysis. This step was crucial to test the existing practices in the context of Jordan and obtain further information compatible with the gap analysis and prior interviews. Additionally, the interviewee’ experiences, judgements, and knowledge could be used to generate as many categories as possible. Step 3 verifies that the findings from the theoretical implications through the gap analysis and interviews could enable additional relevant data to be collected.During the interview process, the collected data were analysed once the interview was complete. The information was then categorised and labelled based on the interview source, facilitating subsequent reviews of the interview data for any missing or unclear information. In addition, this process is necessary when the categories are not well defined, and an interview needs to be reviewed to clarify the category. In some cases, some categories might not be fully developed during the open and axial coding; therefore, the selective coding process further develops these categories. Each category was recorded based on the interview source to also prepare for the subsequent interview questions. Each question could involve several categories, while each category had specific properties and dimensions. These categories were generated as much as possible until a theoretical saturation for each category was achieved. At this point, no more new information would be needed since the interviewees would repeat information.•sustainability in Jordan to confirm that sustainability is not part of project management in Jordan and develop a set of sustainability requirements.General questions about •complexity, including project delivery environment in terms of the availability of natural resources and energy, strategies/policies/objectives, stakeholder relationships and organisation structure.Questions regarding •capability of the client, sponsor, supplier, and market to align behaviours and identify gaps.Questions regarding the Strauss and Corbin These three groups of questions are the core element of the interviews to investigate a way to conduct research in sustainable project management in Jordan. In addition, sub-questions were built based on these. These lists of questions were designed from the gap analysis, which was conducted to explore the gaps between the existing practices of conducting sustainability in Jordan and the international practices of sustainable project management. Reflections from each question group needed to be clarified, along with their implications on the development of the interview questions. The findings from each group were linked to the aim of this research. At each stage, the findings were reflected in the overall process of developing the subsequent questions. However, the findings showed a need for an entire effective process with necessary improvements.•Why is sustainability not embedded into project management practices in Jordan?•What are the advantages and disadvantages of emending sustainability into project management?•Why is the cost of sustainability considered an issue for project management?•How do you determine the need for project management?•At which stage do you think the integration of sustainability in project management is important?•Why does sustainability need to be integrated into this stage?•Who ensures the strategic alignment between sustainability objectives and the organisation's objectives?•How and when do you achieve strategic alignment between them?•Can a process achieve this alignment effectively?•What sustainability requirements are needed in terms of environment, society and economy, and at which stage should they be integrated?The first group of questions aimed to confirm that sustainability practices are not part of project management in Jordan. Moreover, the goal was to understand why. Therefore, in-depth follow-up questions were asked based on the responses in the initial interviews. The list of questions was built, and sub-questions were then derived from those responses. Example questions were as follows:The last question aimed to have the sustainability requirements set out in the strategic objectives of the organisation without any separation. Environmental, social and economic requirements were identified to be considered in project management. These provide general information for ‘who’, ‘why’ and ‘when’ questions regarding sustainable project management in Jordan. As a result, this can yield clear ‘why’ and ‘what’ questions for the rest of the interviewees. The gap analysis found that sustainability is not part of project management in Jordan and that projects are traditionally managed. However, the analysis indicated that sustainability is part of project management in many other countries from the onset of project development, which needs to be considered in the Jordanian context. Therefore, a group of questions was developed to embed these practices of sustainability into project management in Jordan, and project managers in the country were interviewed. To achieve triangulation amongst these interviewees and the collected data from other groups, they were asked subsequent questions to develop ways to improve the overall process of project management with respect to sustainability.•When do these barriers need to be assessed during the strategic planning process?•How do you overcome these barriers?•Who is responsible for this role?•How do you ensure the current organisation conditions are appropriate for adopting sustainability? Who is in charge of this task?•What measures are needed for the strategic alignment of the organisation's objectives and sustainability objectives?•Why are these measures needed? When are they needed? How are these measures adopted, and by whom?•To what extent is the current top-down approach adequate in meeting the sustainability requirements?The second group of questions was about the assessment of complexities (barriers) in project management in Jordan. This group of questions was the first step in the assessment of the organisation and project delivery environment . Many factors act as internal or external barriers to conducting sustainable project management in Jordan – stakeholder engagement, interfaces, technology requirements, and financial impact. Assessing the complexity was essential to clarify the risks and potential revenues of various opportunities. Additionally, the current conditions of the environment delivery and organisation structure could render the adoption of sustainability into project management in Jordan challenging. These are the main assessment elements such that the project is delivered under the sustainability requirements. The assessment can be divided into two sub-groups of questions: (i) the internal and external factors affecting sustainability and (ii) the legal and institutional frameworks towards the strategic alignment of the organisation's objectives and sustainability. The gap analysis indicated that the strategic objectives of sustainability were poorly integrated with the organisation's objectives, overlooking environmental, social, and economic aspects. The existing practices showed that the internal and external barriers were the drivers for complexities, such as water sources, energy environment, and funding. Moreover, administrative measures and the bureaucratic system are the main drivers of the organisation. Therefore, another set of interview questions was derived for the investigation:This second subset of questions yielded an in-depth investigation of the legal and institutional frameworks. Moreover, it determined how the legal and institutional frameworks could achieve the strategic alignment of the organisation's objectives and on-ground reality. Additional questions were asked, such as ‘Do you think there is a need to update the strategic plan as the current frameworks are not stable? If yes, when does the update occur, and by whom?’ For example, •Why do stakeholders not engage in adopting sustainability into project management?•How should the stakeholder engagement look?•When is the integration needed? How can relationships be established between stakeholders?•What is the purpose of engaging stakeholders? Who are they•What tools are needed to engage stakeholders effectively?•Do stakeholders affect the key decisions? How? What decisions can they make?Another issue that can be outlined is the lack of stakeholder engagement. Therefore, the stakeholders need to be engaged from the start of strategic planning. A set of subsequent questions was designed, including the following:•What are the advantages and disadvantages of developing an overall comprehensive strategic plan?•Who will oversee the delivery of these plans? When?•Are there any policies from the government? If so, at which level are they?•How effective are they? Do these policies affect the comprehensive plan?•Do you believe the integration of these policies needs to be checked?•Who checks if these policies are effective?•Does a monitoring system for adopting these policies exist?•How effective are they towards sustainability?The interviewees indicated another issue regarding complexities that the sustainability objectives that come from the strategic planning process through a bottom-up approach achieve only partial sustainability. Moreover, these objectives should be comprehensive and cover all the requirements of sustainability. Therefore, a set of subsequent questions that were designed include the following:•Who owns these decisions?•Which level of management should make these decisions to achieve sustainability?•What are the decisions, and when are they being made? What problems arise with these decisions?•To what extent are these decisions effective toward sustainability?•What measures are needed to improve these decisions toward sustainability?Another barrier occurs during the strategic decision-making process. Decisions are made by the person who assumes the overall responsibility at the top management level. Therefore, the subsequent questions included the following:•What is the main reason for the misalignment?•How do you then achieve coordination amongst the organisations?In addition, the findings outlined that the lack of coordination between the organisations might result in misalignments between them. This issue, as mentioned by an interviewee, outlined the following set of subsequent questions, for example:•How can the key stakeholders take the role of controlling/monitoring the process of sustainable project management in Jordan?The main question, then, is if the current institutional framework is effective for establishing sustainability in project management.•Who are the members of this committee?•Who is the head of this committee?•What are the roles and relationships of the stakeholders in this committee?•When is this committee needed?•What levels of decisions will this committee make?•How can these committees achieve strategic alignment between the organisation's objectives and on-the-ground reality?•How will these committees be monitored?•How can the committee verify the sustainability requirements are achieved?In the gap analysis, an issue arose that the coordination between each party might be achieved by strengthening the institutional framework. Therefore, a subsequent question was, ‘What measures are needed to make the institutional framework effective?’ The answer was to create a higher-level committee. Additional subsequent questions were designed based on the implicationsIn the third group of questions, an in-depth investigation was conducted to align behaviours and identify capability gaps and weaknesses of the client, sponsor, supplier, and market. In this regard, the main aim was to identify a set of programmes and best practices to enable the project's parties to establish sustainability in project management in Jordan. Moreover, this allows public organisations to confirm that all parties understand the definition of sustainability. However, the interviewees’ responses showed some weaknesses and capability gaps of the mentioned parties. As a result, such programmes should be devised for them to build up their capacity, improve their skills and understanding, and transition to a long-term perspective. From the gap analysis building team, capability is an important aspect to develop in those who are engaged in sustainability in project management. •Does the ministry, under the current conditions, have the capability to develop strategic objectives regarding sustainability? If yes, how? If not, where are the capability gaps?•What skills are needed?•How can they affect the development of the strategic objectives such that sustainability is part of project management?Another set of questions was designed to investigate the capability gaps and weaknesses of the mentioned parties to ensure the adoption of sustainability project management in Jordan:•Are there any areas of misalignment between stakeholders, sponsors, clients, and the market?•Do you think that the key advisor/specialist of sustainability is important to be appointed to strengthen the capability of the project's parties? If not, why?•If yes, how the advisor/specialist plays the key role in ensuring the strategic alignment between the ministry objectives regarding sustainability and on-ground reality are realised?Another subsequent group could be outlined in terms of the need for a specialist in sustainability:These groups of questions are considered the core questions which enable us to answer the overall research question to solve the research problem. These groups of questions interplay between the data collection and data analysis for both open coding and axial coding.•Where in the strategic decision-planning process are the updated steps needed?•Do you think such gateways are needed, and where?•Do you think these gateways can affect the overall process of strategic decision-planning? What are the links between these stages?•When can the feedback be provided? Who can give the feedback?•When do you think the updated strategic plan is needed?Once the open and axial coding was undertaken with interviews to generate categories and investigate incidents and their relationships, selective interviews from public and private sectors and academia in strategic and project management were conducted to complete any missing or undeveloped categories and strengthen the relationships between the categories. Five groups of questions were designed for selective coding. Each includes a set of subsequent questions to investigate selected issues that had not been developed or saturated yet, determining which issues still need to be discussed. The interviewees mentioned a need to update the strategic plan and ensure that feedback from the stakeholders is acted upon. Therefore, the first set of questions outlined subsequent questions relating to this issue:•Do you think the higher-level committee is fully developed?•Do you think all these parties that engaged in the higher-level committee are fully developed?•Is any additional party needed? What are the relationships between them?•Do you think the higher-level committee is managing the overall process of strategic planning?•Are there any requirements?Other issues were outlined regarding committee development. The interviewees mentioned a need for a committee to manage the overall process of sustainable project management. Therefore, the relevant subsequent questions include the following:•At which stage do you think the building team capacity is needed?•At which stage do you think that stakeholder identification and engagement are important?•What tools and methods are needed to engage them?•Do you think team-building capacity is needed when the stakeholders are engaged, and when?•How do you ensure these are fully engaged? Do their decisions affect the overall process of strategic planning?The capability gaps mentioned by the interviewees were the major factors affecting the overall process of sustainable project management. However, we still needed to know how the committee could be assessed in terms of its understanding of the sustainability requirements and how stakeholder engagement could benefit from the team-building capacity. In addition, this group of questions could inform the relationships between the building team capacity and stakeholder engagement. The subsequent questions were designed into the open and axial coding, where further necessary information could be obtained through the selective coding process. Therefore, these questions include the following:•Do you think the strategic planning stages are appropriate?•Do you think any improvements to developed stages are needed?•What types of evaluations are needed?•At which stage is the most appropriate feedback needed?•Do you think these processes serve the requirements of sustainability? Why?The following group of questions outlined any feedback and missing data that needed to be obtained. The strategic decision process of sustainable project management seemed underdeveloped and saturated during the open and axial coding, in which some issues required more details. Therefore, questions like the following were posed:•What are the main areas that need to be studied in SWOT analysis? Who performs the analysis? When?•Do you think these areas can improve the overall sustainability practices?Moreover, the interviewees mentioned that conducting the strength, weaknesses, opportunities, and threats (SWOT) analysis was needed at the onset of strategic decision-making. Therefore, a set of questions was designed for an in-depth investigation into such areas relating to sustainability:All these groups from selective coding were carried out at the final stage of data collection. This process defined where more data and clarifications were needed until reaching theoretical saturation. To this end, three persons were interviewed from the public and private sectors.The starting point of the GT process is coding. Two stages were carried out to explore sustainability in project management in Jordan. The first stage of the MGT investigation was simultaneous open and axial coding. The data analysis process involved a study of the collected raw data from the interviews, and then a set of incidents were grouped into appropriate categories. The example below provides insight into how the analysis was carried out line-by-line using the microanalysis method. Two questions are listed from an interview that was conducted in Jordan, and a section of the answer is provided. The relationships between incidents and categories are identified.Question 1. What are the current organisational structure conditions that make the adoption of sustainability in project management complex in Jordan?The current organisation's system needs to be updated regularly as the system seems inadequate for adopting sustainability. The main barrier is the personal interventions that would make the system complex. This means the top managers and key decision-makers do not want to change from traditional behaviours to new ones, and usually, the use of their powers adds complexity. One solution to overcome such complexities is to create a one-stop shop that could solve the issue and save time. The following barriers exist:-Lack of coordination between each party, which causes delays in decision-making.-Bureaucratic system and administrative measures.-People and their culture .-Lack of previous planning and poor strategic planning.-Conflicts and interfaces between the interests of the organisation.Question 2. How do you ensure the alignment of sustainability with the organisation's primary services or delivery objectives?Moreover, the respondent explained an important aspect relating to the current institutional framework that could make the practice of sustainable project management complex. He stated that the misalignment and the missing roles amongst the institutions complicate the adoption of sustainability. He suggested developing top-down and bottom-up approaches to follow the strategy of sustainable development efficiently for sustainable project management in Jordan. The stakeholders will then take the role of evaluating the process of sustainable project management in Jordan and ensuring strategic alignment with the organisation's primary services objectives.This response was driven by one interview, and a microanalysis was carried out during the open and axial coding process. The related data from these interviews were underlined and classified as one of the following: current organisation system, updating the system, personal interventions, key decisions-makers, do not want to change, traditional behaviours, powers of stakeholders and top managers, one-stop shop, lack of coordination between each party, delay for considering the decisions, bureaucratic system and administrative measures, culture , lack of planning and interfaces between the interests. Then, the next questions could classify some incidents as follows: misalignment role and the relationships between the institutions, top-down and bottom-up, structure of stakeholders, evaluating the process of sustainability integration, and strategic alignment of organisations objectives and sustainability. These data were coded to develop a set of categories and the relationships between them. These large datasets are labelled and grouped into appropriate categories, including the following: strategic decision-making, stakeholder engagement, resistance to change, strategic planning, institutional system and monitoring process of strategic planning. During the fieldwork study, the collected data from each interview was immediately analysed line-by-line using microanalysis. This process broke down the collected data into discrete parts, including concepts, incidents, and ideas. Once the researcher found that some issues needed to be confirmed by follow-up interviews, a set of subsequent questions were developed for the confirmation interview to build up the theory. Once similar incidents began to accumulate, their grouping was carried out within a specific category. They were grouped into a wide range of categories with further microanalysis, which was carried out after the interview was recorded.The main goal of open coding is to generate categories and keep them open for any further changes. The researcher continued to investigate further issues until the categories were saturated. Each category grew until reaching a theoretical saturation. However, no specific sample size is defined when theoretical saturation occurs •Strategic decision-making.•Stakeholders’ engagement.•Resistance to change.•Institutional system.•Monitoring system.Strauss and Corbin Therefore, the developed categories and their relationships were clarified based on their similarities and differences. However, the undeveloped categories in their properties, dimensions and relationships were investigated further. As a result, in-depth, subsequent interview questions were posed based on the issues obtained during the axial coding that needed further investigation.– Complexities of delivery environment. Furthermore, during the fieldwork, some of the sites and persons were revisited to investigate further.In selective coding, the poor and undeveloped categories were clarified in the second stage of data collection. The first stage of interviews was conducted with targeted samples from public and private sectors at different organisational levels. The categories at this stage were well-developed, and the relationships amongst them were well-strengthened. The poor or undeveloped categories were clarified, and the overall relationships were filled to achieve consistency and strengthen them around the central category. Once the central category was defined, the theory organised around this central category was defined. The core category was named such that all interviewees could understand it in the context of other research studies Once the integrated theories were agreed upon, the process towards grounding the theory to develop an overall approach to overcome such complexities that affect the adaptation of sustainability in project management in Jordan. This was important for reaching the final level of detail, in which the integrated approach needed to be fully developed in terms of their relationships and gaps for all missing elements were filled.The verification of the research indicated whether the research study's findings were reliable Research ethics is considered a crucial part of the research process. Researchers and participants need to be protected during the research. During the fieldwork, the researcher gave sufficient time, i.e., two weeks, for the interviewees to decide whether to take part in the research. Once they agreed to be part of the research, they were considered for the list of interviewees. If a potential participant provided no response, they were dropped from the list because of the time limit of this research. The decision to take part was solely that of the participant. Once agreeing to participate in this research, they gave permission to use the information they provided for research purposes only, and interview arrangements were made . The researcher conducted each interview. Additionally, the participant could choose if the interview was recorded. Although they were told that their responses would be kept in strict confidence, they could remain anonymous and the collected data would be anonymised and codified, they all preferred not to be recorded.This article describes steps for conducting research using MGT to investigate the existing practices, complexities and capabilities of sustainable project management in Jordan. It also tackles the data collection methods usually used for construction research. In detail, the MGT process explains how the research is conducted. The fieldwork study in Jordan provided the data through semi-structured interviews and document collection. One disadvantage of GT is that it heavily relies on the researcher's interplay between data collection and analysis. Therefore, a gap analysis was conducted to explore the existing practices of project management and sustainability in Jordan. Moreover, the initial stage of the data collection process was undertaken through a pilot study to examine the extent to which the designed set of interview questions provided the expected outcomes. Finally, the current research study proposes a methodology for conducting systematic research in the sustainable project management field that has yet to be applied in the field under study. The use of this method is recommended for similar fields since it gives the research a more solid foundation for better and more reliable results.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.