The synthesis of two-dimensional (2D) transition metals has attracted growing attention for both fundamental and application-oriented investigations, such as 2D magnetism, nanoplasmonics and non-linear optics. However, the large-area synthesis of this class of materials in a single-layer form poses non-trivial difficulties. Here we present the synthesis of a large-area 2D gold layer, stabilized in between silicon carbide and monolayer graphene. We show that the 2D-Au ML is a semiconductor with the valence band maximum 50 meV below the Fermi level. The graphene and gold layers are largely non-interacting, thereby defining a class of van der Waals heterostructure. The 2D-Au bands, exhibit a 225 meV spin-orbit splitting along the  Dimensionality of a material is a critical parameter to control its electronic properties. Here, the authors report that 2D gold transforms from a semiconductor, with valence band maximum 50 meV below the Fermi level, into a metal by tuning the number of layers from 1 to 2 in between graphene and SiC. In particular, there are essentially no single-element materials other than graphite that can be easily exfoliated14. 2D metals see a vast field for applications, ranging from catalysis to sensing16, passing through enhanced magnetism20. This enticing applicative potential has prompted the development of various approaches for the synthesis of low-dimensional metals15. Several chemistry-based strategies have been implemented, however mostly yielding nanostructures of different shapes and geometries15. Physical methods have been shown to effectively yield monolayers of transition metals, typically on other metal surfaces23. The main focus of those types of investigations was the interactions between heavy atoms yielding large spin-orbit splitting of surface states, which might be useful for spintronic devices24. However, the strong interaction between the metallic substrate and the 2D layer typically hinders the possibility to access the intrinsic properties of the latter. Also, keeping the surface energy low enough to avoid the growth of multilayer islands is a non-trivial problem to address and often a capping medium solution must be adopted25.Lowering the dimensionality of a given compound has become a big hype in the field of material research, as this opens the possibility to explore and exploit properties, which are inaccessible in a bulk crystal. While several compounds can be relatively easily rendered two-dimensional (2D) with physical approaches28 or zerolayer graphene (ZLG) on SiC(0001) as well as under epitaxial graphene on Ni(111)29. The effects reported were doping of the graphene π-bands31 or mini-gaps opening in the graphene Dirac cone due to moiré superperiodicity32. It was recently shown that the interaction between the 5d orbitals of gold and the valence band of graphene can open a spin-orbit gap deep in the valence band of gold-intercalated graphene on SiC(0001)33. However, no evidence of two-dimensional dispersing bands stemming from the metal layer was ever reported, which would be indicative of a well-defined order of the film.In this article, we shed a light onto the electronic properties of two-dimensional gold (2D-Au), by synthesizing it via the intercalation of Au atoms at the heterointerface between the Si-terminated SiC(0001) surface and its C-rich  based system34 they can solely be attributed to the interfacial Au layer.Photon energy dependent ARPES measurements were performed to probe a possible crystallographic periodicity along the entclass1pt{minima31. A single gold layer acts as an electron donor to graphene, shifting the π-bands down until the Dirac point E0 is observed about 700 meV under the Fermi level, as visible from Fig. εeff = 7 ± 1, which allow us to detect the plasmaron band35. The crossing energy of the plasmaron band is indicated as E1 and further details can be found in the Supplementary Note The gold atoms at the interface affect the electronic properties of grapheneThe size and shape of the 2D-Au BZ suggest that the Au atoms are arranged on a triangular lattice with the lattice parameter matching that of SiC(0001), i.e., 3.08 Å. As a further support to this hypothesis, we have observed with ARPES, graphene replica bands shifted by a SiC(0001) reciprocal lattice vector (cf. Supplementary Note We compared the observed bands to a tight binding (TB) model calculated on this 2D triangular lattice in the next-nearest neighbor (NNN) approximation:a is the lattice parameter, γ01 and γ02 are the NN and NNN hopping parameters, the first being of the order of 1 eV and γ02≃γ01/10. For the plot of Fig. γ01 = 1.1 eV and a = 3.08 Å, that is the SiC(0001) lattice parameter.k, confirming the right choice of a. The validity of the model also confirms the 2D nature of the states. However, some small deviations are present, especially around Apparently, even this simple model describes the measured band dispersion quite well. In particular, the extremes are placed at the same 36. These simulations show the formation of Au-interface related bands, similar to the ones observed in our experiment. There, it was presumed, that the structure of the interfacial Au is arranged such that every topmost Si atom of the SiC is bound to one Au atom, i.e. a (1 × 1) with respect to the SiC(0001). Similar to our experiment, their bands have the maximum in close proximity to the Fermi level, which indicates a semiconducting behavior.Density functional theory (DFT) calculations have been published for this system by Chuang et al.37 the authors find a strong spin-splitting stemming from spin-orbit coupling. The spin texture there resembles a Rashba-type with a Rashba parameter of 1.638 eVÅ−1. In fact, we do find a strong correspondence to this in the experimental band structure , low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM) measurements. Representative spectra of the Au 4f doublet indicates the presence of atoms in a single chemical environment. The binding energy that we measure is ~350 meV higher than for metallic gold and this excludes the presence of a substantial amount of metallic gold either on the surface or underneath graphene. In contrast, it indicates that Au is bound to Si at the interface, as confirmed by the Si 2p spectrum, which shows a component of bulk SiC and a surface component of Au–Si. Symmetry considerations allow us to conclude that, since the bands we observe are of s-p character, the Au atoms must interact with the 2p Si orbitals by their 5d electrons.The details about the fitting parameters are reported in Supplementary Table 38. What we observe is rather a significant electronic overlap between the topmost Si atoms of the substrate and the intercalated gold layer. The interaction with the substrate stabilizes the gold layer and induces the interfacial order. Notably, Au atoms deposited onto SiC(0001) are observed not to order on the (1 × 1)39, which implies the need for the graphene on top to impose the observed ordering and electronic structure.It should be noted that this does not represent an alloyed silicide layer, which is also reported to have a different (higher) binding energyμ-LEED pattern of Fig. The From the data reported above, we find that every Au atom is bound to a Si atom at the interface . Going from a single Au layer to a Au bilayer does not only switch the doping of graphene from 11 cm−2, which, given a band velocity of (1.33 ± 0.05)⋅106 ms−1, corresponds to a shift of the Fermi level by (−150 ± 10) meV with respect to the Dirac point. We as well observe the Rashba splitting at about −1 eV due to the interaction between the graphene and gold bands, as reported in ref. 33.Figure ky direction, with reference to Fig. 24. Similar states are as well observed for the SC phase, as visible from the ARPES data acquired at 75 and 40 eV, reported in Supplementary Figs. The interfacial gold still develops its own band dispersion, with a rich structure, as exemplary shown in Fig. entclass1pt{minima36, even if they considered three layers at the interface instead of two. Such a band structure implies that at any given small variation of the chemical potential, or applied external voltage, there will always be a finite electronic density of states, confirming the metallicity of this phase.We mark the states reaching the Fermi level with the orange dashed line and a solid circle. The spectral weight at f doublet fitted with two components. The ratio between the two is very close to one, indicating a symmetric distribution of the atoms between the first and the second layer.XPS measurements confirm the presence of a gold double layer, as does STM . This is illustrated by the μLEED, ARPES, and STM measurements. The estimation of the lattice parameter is (2.93 ± 0.01) Å, about 1.6% larger than the nominal 2.883 Å of the Au(111).Such a grid—represented in Fig. a and indicated as a yellow disc in panel c. The difference in C-Au adsorption distance emerges from the local variation of the atomic registry between the lattices.When such a gold bilayer interacts with graphene, it develops a superperiodicity half the size, which is observed in STM, as visible in the data reported in Fig. n = (3.45 ± 0.05)⋅1013 cm−2 when on SC 2D-Au, to p = (9 ± 1)⋅1011 cm−2 when on M 2D-Au. The doping difference, i.e., a shift in the Dirac point position, is about 700 meV and is reflected almost entirely to a work function difference between the two phases , we define a material with semiconductor character, exhibiting the maximum of the valence band at an average energy of 67 meV below the Fermi level. We have determined that the gold atoms arrange themselves in a highly ordered triangular lattice, mimicking the SiC(1 × 1) and develop their own band structure. Such an electronic band dispersion has a truly two-dimensional character and it is notably well reproduced by a simple TB model. Tuning the amount of intercalated gold from one to two layers, leads to a two-dimensional gold with metallic character. The interatomic forces within the gold layer make the lattice parameter shrink from 3.08 Å, to 2.93 Å, yet not quite relaxed into the Au(111) configuration, which has 2.88 Å as atomic spacing. Graphene is also affected by the underlying 2D gold in terms of electronic properties. Its doping level goes from Besides the deep fundamental interest provided by this class of materials, we envision a vast portfolio of possible applications for this system, ranging from detection of THz radiation, to more sophisticated optoelectronic devices involving the spin degree of freedom. It will moreover serve as a platform for exploring non-linear optics effects in two-dimensional gold, a field so far essentially unexplored.n-type substrates were used in the present study and were purchased from SiCrystal GmbH. Polishing damages were removed by etching the substrate at 1500 °C in a purified H2 atmosphere. The SiC(0001) surfaces were graphitized by annealing the samples in argon atmosphere following the procedure introduced by Emtsev et al. in ref. 40. The ZLG develops upon annealing in Ar atmosphere at about 1400 °C for 10 min45. The formation of the ZLG results in a carbon-rich reconstruction with periodicity  and that they do not require any particular protection from the atmospheric environment. In UHV conditions, they can be heated up to 850 °C before the intercalated gold starts to be deintercalated and desorbed from the surface.Nominally on-axis oriented single crystalline single-side polished 6H-SiC 2 of the BESSY II  synchrotron facility at a temperature of 90 K. The hemispherical electron analyzer used for the data harvesting was a Scienta R8000 with a diameter of 200 mm and an ultimate energy resolution of 1 meV. In our experiments the instrumental resolution was set to about 2.5 meV, hence smaller than the thermal broadening of the bands, i.e., about 7.5 meV. Additional ARPES measurements have been carried out at the I4 end-station of the MAXlab  synchrotron facility with a SPECS Phoibos 100 analyzer. The aforementioned lines have also been used to acquire X-ray photoelectron spectroscopy (XPS) data. Preliminary studies to clarify the preparation procedures and to assess the sample’s quality were carried out in the home-laboratory at the MPI Stuttgart using a Specs Phoibos 150 analyzer and monochromatized He II radiation for the photoexcitation. Low-energy electron microscopy (LEEM) measurements, as well as micro-ARPES (μARPES), micro-LEED (μLEED), and micro-XPS, were acquired at the beamline I311 beamline of the Maxlab using an Elmitec III microscope. More details about the performances of the microscope can be found elsewhere48. The scanning tunneling microscopy (STM) measurements were performed with an Omicron LT-STM microscope at the CNI@NEST in Pisa at a temperature of 78 K.The band structure of the system was mapped by means of ARPES at the end-station 1Supplementary Information


Accordingly, graphene and MoS2 have been widely studied to be applied in the development of biosensors. Moreover, nanohybrid materials developed by hybridization of graphene and MoS2 have a huge potential for developing various types of outstanding biosensors, like electrochemical-, optical-, or surface-enhanced Raman spectroscopy (SERS)-based biosensors. In this review, we will focus on materials such as graphene and MoS2. Next, their application will be discussed with regard to the development of highly sensitive biosensors based on graphene, MoS2, and nanohybrid materials composed of graphene and MoS2. In conclusion, this review will provide interdisciplinary knowledge about graphene/MoS2 nanohybrids to be applied to the biomedical field, particularly biosensors.Graphene has been studied a lot in different scientific fields because of its unique properties, including its superior conductivity, plasmonic property, and biocompatibility. More recently, transition metal dicharcogenide (TMD) nanomaterials, beyond graphene, have been widely researched due to their exceptional properties. Among the various TMD nanomaterials, molybdenum disulfide (MoS Ever since their unique properties were first reported, nanomaterials have been widely researched and applied in various scientific fields ,2. In ge2) are two of the most commonly studied materials being researched in recent years . T. T88]. Tty of GO . In addity of GO .In addition to electrochemical biosensors, graphene and GO have been widely employed to develop SERS-based biosensors due to the graphene-enhanced Raman scattering . For exa3+, cytochrome C (Cyt C), and phosphate (Pi), as shown in 3+ is an important ion that acts as a co-cofactor in metalloproteins, and it is also known to cause neurodegenerative diseases and organ dysfunction when it is present in excess in humans 3−/4−-containing solution with square wave voltammetry. The [Fe(CN)6]3−/4− was used as a redox probe and exhibited a current value through the electron transfer process with the surface of the HIV biosensor. When the gp120 was added and combined with the gp120 antibody on the Au/MoS2/Au multilayer, the redox signal from [Fe(CN)6]3−/4− was blocked, decreasing the measured current due to the nonconductivity of the captured gp120. The decreasing current value was linearly proportional to the added gp120 concentration, enabling the sensitive detection of gp120 concentration. Using this HIV biosensor, the gp120 was measured with a linear response in a broad concentration range of 0.1 pg/mL to 10 ng/mL. Because of the effective electron transfer and large surface area of the MoS2 NPs, it showed higher current values compared to the normal Au substrate prepared without MoS2 NPs. Based on the detection limit of 0.066 pg/mL, it was proved that gp120 was measured more sensitively than in other electrochemical HIV biosensors previously reported. One example of a MoSubstrate . To devect gp120 a. The de2 nanosheet and lactate oxidase (LOx) . . 2 nanos+) biosensor composed of a MoS2 nanosheet and FITC-attached ssDNA (FITC–ssDNA) . . 2 nanos2 QD and MnO2 nanosheet . T. T2 nanoosensors ,142,143.lication . During 2 nanohybrid, such as the 3D graphene/MoS2 aerogel and rGO decorated with MoS2 QDs . T. T2 nano 10−7 M) ,163.2 nanohybrid is being utilized to develop outstanding biosensors with high sensitivity and selectivity. In addition, there are some researchers trying to utilize the graphene/MoS2 nanohybrid to develop wearable or flexible biosensors and electronic devices [2 nanohybrid is expected to play a role as a key component in the development of next-generation biosensors. All of the studies discussed in detail in this section are summarized in As discussed in this section, the graphene/MoS devices ,165,166.2 are particularly promising nanomaterials for highly sensitive and selective biosensors. Graphene, with 2D single carbon atomic layers arranged in a honeycomb lattice structure, possesses the most exceptional properties among numerous carbon-based nanomaterials, such as high conductivity, biocompatibility, and large surface area. TMD nanomaterials have also been studied recently because of their direct bandgap, optical, semiconducting, and electrical properties. These two nanomaterials can both help achieve high sensitivity and selectivity in biosensors and are also suitable for conjugation with biomolecules because of their excellent biocompatibility. Moreover, in recent years, studies have been conducted to create biosensors with graphene/MoS2 nanohybrids to achieve synergistic effects from each nanomaterial.Since nanomaterials were first discovered, numerous nanomaterials have been synthesized, researched, and applied in many scientific fields because of their unique properties. Among the many nanomaterials, graphene and MoS2, and graphene/MoS2 nanohybrids. The discussion was organized into four categories. First, the properties of graphene and MoS2, the synergistic effects derived from the conjugation of graphene and MoS2, and their advantages for developing the biosensors were provided. Next, graphene-based biosensors were discussed that employ an excellent electron transfer facilitation, quenching, and chemical enhancement effects for developing biosensors. Then, MoS2-based biosensors were described. These biosensors utilize the unique characteristics of the MoS2 in various structures, such as its luminescence and electrochemical properties. Finally, recent biosensors based on a graphene/MoS2 nanohybrid were discussed. These biosensors incorporated various structures of the graphene/MoS2 nanohybrid, which provide the advantages of each material and induce exceptional synergetic effects. Although various types of graphene/MoS2 nanohybrid have shown potential for biosensing application, there are still issues to be solved for practical or future applications. Above all else, a uniform mass production, the commercialization of various types of graphene/MoS2 nanohybrid, and reducing the production cost are essential for conducting efficient researches. Nevertheless, it is clear that a graphene/MoS2 nanohybrid is one of the most advanced nanomaterials for next-generation biosensors. In addition, through research to find more efficient types or structures of graphene/MoS2 nanohybrids, these can be used in wearable biosensors or applied to commercially available POCT. In conclusion, the recent research covered in this review, based on graphene/MoS2 nanohybrids, provides a new approach and interdisciplinary knowledge to advance the development of highly sensitive and selective biosensors.This review discusses recently reported biosensors based on graphene, MoS


The surface morphology and electronic structure of hexagonal graphene onion rings (HGORs), a modified graphene structure, were investigated to confirm the possibility as an efficient catalyst when compared to graphene. After confirming the formation of HGORs with a smaller width (~4.2 μm) from scanning electron microscopy (SEM) and optical microscopy images, we compared the catalytic activities of HGORs and graphene by measuring the rate of oxidation of thiophenol using high-resolution photoemission spectroscopy (HRPES). In addition, we also assessed in 4-chlorophenol degradation and the OH radical formation with a benzoic acid to confirm the possibility for photocatalytic activities of HGORs. As a result, we confirmed that HGORs, which has an increased active site due to its three-dimensional structure formed by the reaction of graphene with hydrogen, can act as an effective catalyst. In addition, we could also realize the possibility of optical applicability by observing the 0.13 eV of band gap opening of HGORs. This is because of the unusual optical and electronic properties of graphene that can be influenced by its conformation5. This dependence on conformation can be very useful in various applications including electronic devices, catalysts, and biosensors11. Hence, research aimed at finding new electronic characteristics of graphene has attracted great attention in recent times14.Following the discovery of graphene, there has been a great effort to exploit its unique properties in various applications16. If it is possible to increase the number of active sites (broken structure of sp2 symmetry) to improve catalytic properties by making structural changes while maintaining the intrinsic properties of graphene, an efficient graphene-based catalyst can be realized.Particularly with respect to the applications of graphene-based catalysts, it is likely to be a highly efficient and a low-cost useful material. However, currently-used methods to grow graphene have fundamental limitations that are related to its two dimensional inertness. In other words, the graphene itself exhibits a low catalytic activity due to the limited number of active sites that enable the catalytic reaction17. In detail, it is expected that the inherent properties of the graphene itself can be somewhat weakened by the 3D structure of the graphene derivative. On the other hand, an enhancement in reactivity is expected near the 3D structure is expected, which could increase the reactivity of the material in different ways including enhanced catalytic activity20.Recently, it has been reported that a three-dimensional (3D) graphene derivative called as hexagonal graphene onion rings (HGORs) can be synthesized by regulating the hydrogen partial pressure and it could be a candidate graphene-based catalyst materialin situ growth of graphene. Briefly, by incorporating hydrogen (H2) into graphene grown on a SiC(0001) surface, we successfully fabricated 3D HGORs by controlling the H2 partial pressure and annealing temperature. Furthermore, using scanning electron microscopy (SEM), optical microscope, Raman spectroscopy, high-resolution photoemission spectroscopy (HRPES), and angle-resolved photoemission spectroscopy (ARPES), we have compared the morphologies and electronic properties of the fabricated HGORs with those of graphene.To investigate this possibility as a useful catalyst, we fabricated 3D hexagonal graphene structures with shapes resembling onion rings  by via HRPES, because the thiol group (-SH) in TP can be oxidized to form a disulfide group (-S-S-)22. In addition, to confirm the possibility of HGORs as a photocatalyst, we also assessed the photocatalytic activities of the three tested graphene-related materials in other reactions such as 4-chlorophenol (4-CP) degradation and OH radical formation of benzoic acid (BA) in aqueous solutions, which are widely used to compare the photocatalytic properties of catalyst materials26.Following the comparison of the morphological characteristics and electronic structures of the three distinct graphene-related materials , and HGORs), we assessed their catalytic activities for the oxidation of thiophenol (TP) under 365 nm-wavelength UV light illumination 27. Figure s) (Ts = 1650 K and Ts = 1830 K) under a hydrogen gas dose of ~760 Torr. The images in Fig. s = 1650 K  where desorption of a zipper-like material at the step edges was observed. Si–C sheets were removed in a layer-by-layer fashion, first leading to large terraces with straight rims28. And at the end of this process, an atomically smooth surface is formed. Our result is also in accordance with these observations, and in our case, we find in addition, that HGORs structures can be formed when the surface is passivated by H2 with partial pressure ~760 Torr as illustrated in Supplementary Material Fig. Recently, Glass K-edge XAS. As shown in Fig. s → π* peak at 285.5 eV (marked A) and by the typical line shape of the 1 s → σ* edge at 292.4 eV (marked D). However, a closer look reveals that the intensities of B (286.5 eV) and C (289.3 eV) peaks are higher for the HGORs structure. Hence, this difference of the electronic structure can be explained to be due to contributions from peaks induced by hydrogen30. In other words, when comparing the XAS spectra for the three tested samples, the most significant difference between graphene and HGORs is the increments of these two peaks due to hydrogen doping, while the basic electronic structure of graphene remains the same (black color).To clarify the differences in electronic structure of the three tested samples, we also performed carbon et al. first reported well-formed and regularly shaped ~100-μm-wide HGORs grown on a Cu foil17. Our HGORs structure also shows a regular shape, but with a smaller width (~4.2 μm). In view of its smaller size, we expect that the HGORs fabricated in the work could be useful in practical applications. Figure From the optical microscope image in Fig. 2 partial pressure was investigated, but no significant difference was found for partial pressures in the range 700–760 Torr. Once the optimal conditions for fabricating HGORs were determined, HRPES, Raman spectroscopy, and ARPES were performed to observe the difference in the electron structure of HGORs from that of graphene.To confirm the effect of hydrogenation on the structure, the influence of Hs core-level spectra of the graphene layer grown on the SiC(0001) surface; sp2 carbon atoms at the interface layer (marked as S2), the 6√3 × 6√3 interface layer (buffer layer marked S1), the graphene layer (marked as G), and the SiC substrate (marked as SiC)32.As shown in Supplementary Material Fig. s core-level spectra  and 1320 cm–1 (D peak) resulting from the graphene layer34. In detail, comparing the intensity ratios of ID/ IG for three samples, it can be seen that m-HGORs and HGORs have values of 0.348 and 0.642, respectively, while graphene is that of 0.218. As is well known, the increased intensity ratio is a good explanation for the 3D structure formation via hydrogen doping in HGORs, which means that a new interface structure has been formed, unlike graphene. In addition, since the peak at 1627.9 cm−1, which is indicated by D’, is the peak due to the defect induced structure of the samples and the intensity of the peak of HGORs is larger than that of graphene, it can be also explained as the difference of electronic structure between graphene and HGORs. As shown in these figures, apart from the change in intensity of the peaks due to hydrogen doping, the general characteristics of graphene are maintained for the other two samples.Figure F) and the Dirac point (ED). As shown in Fig. 36. Based on this result, changes in bandgap of modified m-HGORs and HGORs were measured from the ARPES spectrum, meaning that the band gap energy was estimated from the change in energy gap between the Fermi level and the Dirac point of the two samples. From Fig. For graphene, the absence of bandgap is a major disadvantage that limits its application as an optical material. In order to have semiconductor characteristics, it is necessary to have some degree of gap opening. Therefore, it is important to determine whether HGORs has a measurable band gap. To do this, we measured the difference in band gap between the three tested samples using ARPES. Figure To evaluate the application potential of HGORs, we tested its possibility, which can act as a catalyst. More specifically, we assessed the catalytic activation of TP oxidation see Fig. , and 4-Cp core level spectra of 360 L TP adsorbed on the three tested samples under UV illumination. All the spectra show two distinct S 2p3/2 peaks at 161.5 and 162.9 eV, corresponding, respectively, to the C-SH unbound state (denoted as S1) and the disulfide state (denoted as S2)39; note that the disulfide peak is formed from by the oxidation of the thiol group of TP. Because it has been shown that disulfide is an oxidation product of the thiol group [see Eq.  against time, a first order-reaction relationship was obtained. As shown in Fig. k) for the change in concentration (ln(C/C0)) with time (min.) for the three tested samples. In detail, the apparent rate constant for the decay of the reactant for HGORs was 1.41 × 10−2 min−1 when using HGORs, faster than the cases using other tested samples (8.89 × 10−4 min−1 for graphene and 6.68 × 10−3 min−1 for m-HGORs). As mentioned above, the improvement of the catalytic properties of HGORs has previously been shown to be closely related to the 3D structure induced by hydrogen doping in he samples. Electrons and holes so produced react with aqueous 4-CP solution to generate OH radicals that are capable of effectively degrading the 4-CP solution40.Figure p-Hydroxyl benzoic acid (p-HBA) is formed. Hence, by comparing the amount of the p-HBA formed at a given time, the influence of the OH radical on the catalytic reaction can be analysed and compared26. Results in Fig. Our results are also consistent with the assumption that active radicals are formed on the surface of HGORs, since the reaction of OH ions with holes in HGORs has been shown to usually generate more OH radicals. To confirm the generation of a large number of OH radicals on HGORs, the radical reaction of benzoic acid was performed on these substrates. When the OH radical formed on the surface of a graphene-based sample reacts with benzoic acid (BA) as shown in Eq. , p-HydroThe results are also consistent with those obtained in TP oxidation and 4-CP degradation experiments. Therefore, our results proved that the 3D structure of graphene induced by hydrogen doping can enhance the catalytic activity by forming many active sites (or defect structure).Finally, HGORs exhibiting catalytic properties must be able to maintain their properties after reuse because economic considerations must be taken into consideration in order to be applicable to various fields. Therefore, the reaction by the 4-CP degradation and the OH radical formation of BA using the HGORs, which showed good efficiency among the three tested samples. In particular, because the inertness is one of the most important features of graphene, it is very important to confirm the reuse rate for HGORs in various fields.p-HBA obtained from the OH radical formation of BA were reduced by only ~10.7 and 12.7% in HGORs after 5 re-use. This result was very meaningful that the HGORs shows some practical possibility, which can be applicable in the field of catalysis. Through the additional experiments, we can confirm that HGORs shows some practical applicability because it shows some degree of re-use as well as photocatalytic properties.To test this, re-use experiments for 4-CP degradation and OH radical formation of the HGORs were run for 5 cycles shown in Fig. via HRPES. Furthermore, we also monitored the photocatalytic activity through the rate of 4-CP degradation and the concentration of OH radical formation with BA. Results of spectroscopic analyses clearly confirmed that HGORs can be potentially used as an effective catalyst with a bandgap opening (~0.13 eV) due to the creation of active sites by hydrogen doping. We further expect that the modified graphene such as HGORs will continue to be used by controlling the active sites in manufacturing the modified graphene as an efficient catalyst in the field of nanoscience.In conclusion, we successfully fabricated HGORs with a regular size (~4.2 µm width) from graphene grown on the SiC(0001) surface by reaction with hydrogen. In order to compare the catalytic activities of graphene and HGORs in oxidation reactions, we tested the three materials in the oxidation of TP D = 9 × 1017 cm–3) Si-terminated 6H-SiC(0001) was purchased from Cree Research (USA). Thiophenol (TP: 97% purity), 4-chlorophenol (4-CP: 97% purity), and benzoic acid (BA: 98% purity) were purchased from Sigma Aldrich (Korea).Nitrogen-doped  surface. Prior to graphene formation, the temperature of the SiC(0001) surface was increased stepwise to 1120 K and left overnight for outgassing the substrate. The outgassing was completed at 1200 K and the samples were then annealed at this temperature for 5 min using a silicon dozer (1 Å/min) to obtain a Si-rich surface, the sample temperature was further increased to 1500 K and held for 2 min to form the graphene layer on the substrate. The sample was outgassed again overnight after the formation of a graphene monolayer and then placed in the preparation chamber filled with H+ ion laser  excitation source and a spectrometer (Horiba Jobin Yvon TRIAX 550). HRPES, X-ray absorption spectroscopy (XAS), and angle-resolved photoemission spectroscopy (ARPES) experiments were carried out using an electron analyser  at the 10A2 beamline (Pohang Accelerator Laboratory) to identify the electronic structure of the three tested samples. The C 1 s and S 2p core level spectra were obtained by using photon energies of 330 and 230 eV respectively to enhance the surface sensitivity. The binding energies of the core level spectra were determined with respect to the binding energies (EB = 84.0 eV) of the clean Au 4 f core level for the same photon energy. For photocatalytic activity test, we used 4-chlorophenol  and benzoic acid , as target contaminants. The required amount of the three different graphene-based samples  was prepared in a reactor containing an aqueous solution of each substrate . The suspensions were magnetically stirred in the dark for 20 minutes to establish absorption–desorption equilibrium. Then, the reactor was irradiated by a 300-W Xe arc lamp (Newport) with a cutoff filter for UV illumination (the wavelength was 320 nm). Solution samples including 4-CP (or BA) were collected using a 1-mL syringe every 15 min, filtered through 0.45 µm PTFE filter (Whatman), and then, analyzed. The concentrations of 4-chlorophenol and p-HBA were measured by high-performance liquid chromatography  equipped with a diode array detector and a Shim-pack GIS column (4.6 mm × 250 mm).The sample morphology was analysed using field-emission SEM . Raman spectra data were obtained with an ArSupplementary Information.


To develop and validate a risk assessment model for the prediction of the acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) in patients with idiopathic pulmonary fibrosis (IPF).  We enrolled a total of 110 patients with IPF, hospitalized or treated as outpatients at Xuzhou Traditional Chinese Medicine Hospital Affiliated to Nanjing University of Chinese Medicine from July 2012 to July 2020. Of these, 78 and 32 patients were randomly assigned to training and test groups, respectively. The risk factors for AE-IPF were analyzed using logistic regression analysis, and a nomographic model was constructed. The accuracy, degree of calibration, and clinical usefulness of the model were assessed with the consistency index (C-index), calibration diagram, and decision curve analysis (DCA). Finally, the stability of the model was tested using internal validation.  The results of logistic regression analysis showed that a history of occupational exposure, diabetes mellitus (DM), essential hypertension (EH), and diffusion capacity for carbon monoxide (DLCO)% predicted were independent risk factors for AE-IPF prediction. The nomographic model was constructed based on these independent risk factors, and the C-index was 0.80. The C-index for the internal validation was 0.75, suggesting that the model had good accuracy. The decision curve indicated that for a threshold value of 0.04–0.66, greater clinical benefit was obtained with the AE-IPF risk prediction model.  A customized AE-IPF prediction model based on a history of occupational exposure, DM, EH, and DLCO% predicted provided a reference for the clinical prediction of AE-IPF. Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by severe pulmonary tissue fibrosis without a known pathogenesis; the mean survival time after diagnosis is 2–3 years. The occAE-IPF was first reported in 1984. Yoshimura et al. briefly reported the symptoms and mortality rate of AE-IPF and identified the efficacy of a large dosage of glucocorticoids . It was Although multiple retrospective studies have reported on the incidence and mortality rate of AE-IPF, a consensus has not been reached. This can be attributed to the different study designs, inconsistent standards for disease diagnosis, few cases, and loss of patients to follow-up . In a reCurrently, there are no effective therapies for the treatment of AE-IPF. Internationally acknowledged suggestions include supportive nursing and glucocorticoid treatment which aim to alleviate symptoms and rectify hyperemia; however, the effects of these strategies are limited . TherefoPatients with IPF who were hospitalized in or visited Xuzhou Traditional Chinese Medicine Hospital Affiliated to Nanjing University of Chinese Medicine from July 2012 to July 2020 were enrolled in the present study. In total, 110 patients were included; 78 patients were selected for the construction of the risk analysis model, and the remaining 32 patients were used to test the model. For patients with multiple hospitalizations or visits, the data from the first hospitalization or visit were adopted. The patients provided written informed consent for inclusion in this study, and the study was approved by the Ethics Commission of Xuzhou Hospital of Traditional Chinese Medicine (ID: XZTCM2018LSY-013).Patients with IPF were confirmed based on clinical features, imaging data, and medical history according to the diagnostic criteria for IPF (2011) which included the following: (1) interstitial pneumonia with known etiology  and (2) HRCT-indicated UIP or suspected UIP symptoms . The diaN-acetylcysteine (NAC), pirfenidone (PFD), glucocorticoid (GC), and acid-inhibitory drugs.Clinical data were obtained from the medical history of the patients during hospitalization and the follow-up visits. The data included the following: (1) patient characteristics, such as age, sex, occupational history, and history of smoking; (2) complications, such as diabetes mellitus (DM), essential hypertension (EH), coronary heart disease (CHD), cerebral infarction (CI), hypothyroidism, gastroesophageal reflux disease (GERD), and obstructive sleep apnea-hypopnea syndrome (OSAHS); (3) lung function test indices, such as Forced Vital Capacity (FVC)% predicted and diffusing capacity for carbon monoxide (DLCO)% predicted; and (4) medical treatment, including pvalue as characteristics; a p value of <0.05 was considered statistically significant. Factors describing statistical significance were used to construct the nomogram using the “rms” program to create a prediction model. To test the accuracy of the prediction model, we used the “rms” program to calculate the consistency index (C-index). The degree of calibration was evaluated by constructing a calibration curve; the closer the calibration curve of the prediction model to the standard curve, the better the consistency of the prediction model. The area under curve (AUC) value of the model was calculated to predict the degree of discrimination of the prediction model, with a higher AUC value representing a higher degree of discrimination. By quantifying the net benefits of the probability of different threshold values in the array, decision curve analysis (DCA) was used to determine the clinical usefulness of the nomogram. Finally, an internal validation method was used to test the stability of the prediction model; the “rms” program package was used to calculate the C-index and AUC value for the 32 patients with IPF in the test group.All clinical data are shown as count (%) and were analyzed with R version 3.6.3 . The Caret package in R was used to randomly assign the 110 patients to the training and test groups in a ratio of 7 : 3 . Information on the training group was subjected to multivariate logistic regression with the odds ratio, 95% confidence interval, andIn total, 110 patients with IPF, treated as inpatients or outpatients between July 2012 and July 2020, were enrolled in the present study. In the training group (78 cases), there were 16 patients with AE-IPF (20.51%), while in the test group (32 cases), there were four patients with AE-IPF (12.50%). All the patients' clinical data, including demographic and clinical characteristics, complications, lung function, and medication, are presented in p < 0.01), DM (p < 0.01), EH (p < 0.01), and DLCO%-predicted lung function (p < 0.05) were identified as the risk factors for AE-IPF (The clinical data of the training group were entered into the multivariate logistic regression model to obtain the coefficients of the corresponding characteristic variables. Among the variables, a history of occupational exposure (r AE-IPF .Based on the results of the logistic regression, we determined the predictive factors for AE-IPF. To facilitate the estimation of the risk for AE-IPF, we screened the four characteristic variables and then constructed a nomographic risk prediction model. Each variable was scored on a scale, and the range of the total score was 0–220. The total score on the AE-IPF risk axis represents the probability of AE-IPF. The higher the score, the higher the risk that a patient with IPF will develop AE-IPF .x-axis represents the predicted risk for AE-IPF, and the y-axis represents the realization of AE-IPF. The bidiagonal dotted line represents the prediction of an ideal model, and the solid line represents the realized prediction capacity. The closer the dotted line is to the bidiagonal line, the greater the prediction capacity. The results of the present study showed a preferable consistency between the nomographic model and the ideal model.We constructed calibration curves to facilitate the assessment of the degree of calibration of the risk prediction model of AE-IPF. As shown in To test the accuracy of the model, we first calculated the C-index. An ROC curve indicates that the predictions are close to random guesses. Meanwhile, when an ROC curve is plotted, we can use AUC to measure the performance of the predictor. We then calculated the AUC value of the model and constructed an ROC curve . Based oTo further evaluate the stability of the AE-IPF risk prediction model, we calculated the C-index and AUC values of the 32 patients with IPF in the test group using the internal validation group. The C-index value was 0.75, and after constructing the ROC curve to calculate the AUC value for further validation, the AUC value was 0.70 . Therefoy-axis indicates the net benefit, and the x-axis represents the probability of the threshold value. The black solid line represents no intervention, at which the net benefit is zero. The black dotted line represents the intervention, and the net benefit is an oblique line with a negative slope. The blue solid line represents the realized profits of the AE-IPF risk prediction model. The decision curve showed that the greatest clinical benefit will be obtained from the AE-IPF risk prediction model at threshold values of 0.04–0.66.DCA was used to evaluate whether the prediction model could improve clinical decision-making. The decision curve of the prediction model is shown in At present, the cause of AE-IPF is unknown. Recurrent local outbreaks of alveolar damage may lead to the progression of IPF . For somBased on the prediction model, occupational exposure is a major risk factor for AE-IPF. Therefore, workers engaged in ore mining, construction work, inorganic dust production, and chemical processing and manufacturing, and those exposed to organic dust production, are at high risk. Owing to a lack of research, the association between occupational exposure and a strong predisposition toward AE-IPF is unknown. It is likely that when productive chemicals with systemic toxicity enter the respiratory tract in the form of aerosols or gas, they readily enter the blood flow through the vascular bed in the lung, leading to respiratory system damage, systemic poisoning, and AE-IPF.In addition to IPF itself, some patients with IPF also have other complications, which may also induce AE-IPF . AccordiLung function measurement is an important method for IPF diagnosis and for assessing the state of illness . AccordiTo evaluate the accuracy of the prediction model, we first calculated the C-index and AUC values. The C-index was 0.80, and the AUC value was 0.77, suggesting that the AE-IPF risk prediction model has an acceptable accuracy. To further examine the stability of the prediction model, we used an internal validation method, by evaluating the clinical data of the 32 patients with IPF in the test group, and then calculated the C-index and AUC values. The C-index and AUC values were 0.75 and 0.70, respectively. The results of the internal validation thus suggest acceptable stability of the AE-IPF risk prediction model.A history of occupational exposure, DM, EH, and DLCO% predicted were risk factors for AE-IPF as determined by the logistic regression analysis, and the AE-IPF risk prediction model was successfully constructed by creating a nomogram. The nomogram could clearly and intuitively predict the probability of IPF patients' progress to AE-IPF, thus supplying a reference for clinical progression. However, the current study was a single-center retrospective study with a limited sample size. Therefore, the results of this study should be confirmed in a prospective multicenter, large-scale study. In addition, hierarchical studies of patients of different ages or with different illness severities should also be performed.


It is demonstrated that net optical gain can be achieved via topologically protected four-wave mixing in a graphene metasurface. 13 W−1 m−1, i.e., more than 10 orders of magnitude larger than that of commonly used, highly nonlinear silicon photonic nanowires. These findings could pave a new way for developing ultralow-power-consumption, highly integrated, and robust active photonic systems at deep-subwavelength scale for applications in quantum communications and information processing.We study topologically protected four-wave mixing (FWM) interactions in a plasmonic metasurface consisting of a periodic array of nanoholes in a graphene sheet, which exhibits a wide topological bandgap at terahertz frequencies upon the breaking of time reversal symmetry by a static magnetic field. We demonstrate that due to the significant nonlinearity enhancement and large life time of graphene plasmons in specific configurations, a net gain of FWM interaction of plasmonic edge states located in the topological bandgap can be achieved with a pump power of less than 10 nW. In particular, we find that the effective nonlinear edge-waveguide coefficient is about γ ≃ 1.1 × 10 In the past decade, topological photonics has emerged as a rapidly burgeoning field of exploration of topological physics ideas framed in the context of photonics. This area of research began with the theoretical work by Haldane and Raghu  interactions in a graphene metasurface upon the breaking of time reversal symmetry by a static magnetic field. In particular, we show that due to large optical near-field enhancement and large life time of graphene plasmons in such metasurfaces, a net gain of FWM interaction of plasmonic edge states located in the topological bandgap can be achieved at an ultralow pump power of less than 10 nW. This remarkable feature is a direct consequence of the unusually large effective nonlinear edge-waveguide coefficient, γ ≃ 1.1 × 10We study a topologically protected nonlinear FWM process in a graphene plasmonic system. Graphene distinguishes itself as an ideal platform to study nonlinear topological photonics in several key aspects: First, graphene exhibits large nonlinearity over a broad spectral range, from terahertz to visible light. In particular, it has been shown  in The nonlinear system explored in this work is illustrated in a and air hole radius r) and the first Brillouin zone of the system used in our simulations are shown in a = 400 nm, r = 120 nm) at different magnetic fields B = 0,2,5,7,10 T are presented in EF = 0.2 eV, vF = 106 ms−1, and τ = 50 ps .We first study the linear optical response of our graphene plasmonic system by calculating its photonic band structure using a numerical approach based on the finite element method (FEM). The unit cell (with lattice constant B = 0), due to the hexagonal symmetry of the metasurface structure, Dirac cones that are protected by the parity (P) inversion and time reversal (T) symmetries exist at K and K′ symmetry points of the Brillouin zone (B ≠ 0), the time reversal symmetry of the system is broken and, consequently, the Dirac cones are gapped out, resulting in a topological nontrivial bandgap. Moreover, the width ∆v of this bandgap increases as the amplitude of the magnetic field increases.There are several notable features of the results presented in y axis, i.e., the number of unit cells along this direction is finite (chosen to be 20 in our FEM simulations), whereas the system is periodic along the x axis , with the gap width ∆v increasing as the amplitude of magnetic field increases. However, different from the band diagrams of an infinite graphene metasurface shown in The projected band diagrams along vg = ∂ω/∂k, within the topological bandgap is either positive (top edge) or negative (bottom edge).One can also calculate the gap Chern number, which is a topological invariant that characterizes the topological properties of the bandgap, to further confirm that the bandgap discussed above is topologically nontrivial and that these edge modes are topological modes  depicted by a red triangle in To gain deeper insights into the physical properties of plasmonic bulk and edge modes of the graphene metasurface, the near-field distribution of these modes propagating in a finite graphene plasmonic metasurface , corresponding to an FWM process in which a pump edge mode with wave vector kp gives rise to signal and idler edge modes with wave vectors ks and ki, respectively. In particular, the exchange of energy among the interacting waves is most efficient when the phase matching condition ∆κ = 0 is satisfied. Unlike the wave vector, the energy is conserved in the FWM process, meaning 2vp = vs + vi.To illustrate these ideas, in what follows, we analyze the circumstances in which the phase matching condition in a degenerate FWM of one-way edge modes can be fulfilled. To this end, we calculate the normalized wave vector mismatch, defined as Δκ ≡ αΔk = −5. More specifically, for frequencies inside the domain defined by this contour, energy is transferred from the pump to the signal and idler over a distance of about 105π lattice constants.Starting from the mode dispersion curves of the topological edge modes presented in vp = 13.17 THz, vs = 13.72 THz, and vi = 12.62 THz, and for which the FWM interaction is nearly phase matched (Δκ = 5.16 × 10−6). Moreover, we considered a seeded FWM process in which the input intensity of the signal is much smaller than that of the pump, whereas the input intensity of the idler is set to zero. Specifically, in our FEM simulations, we set the source input field amplitudes at the three frequencies ∣Ep∣ = 2 × 104 V m−1, ∣Es∣ = 4 × 102 V m−1, and ∣Ei∣ = 0. Last, the nonlinearity of graphene under the influence of a magnetic field of 10 T is described by a third-order susceptibility with value of χ(3) = 5 × 10−10 m2 V2 , which is more than 10 orders of magnitude larger than that of silicon photonic wire waveguides  and the off-diagonal elements  can be determined using Kubo’s formalism (0 = e2EFτ/(πℏ2), τ is the relaxation time (plasmon lifetime), B⊥, vF, and EF being the external static magnetic field perpendicular onto the graphene surface, the graphene Fermi velocity, and the Fermi energy, respectively.In our modeling of an infinite graphene metasurface, periodic boundary conditions are used for the four edges of the unit cell depicted in The surface conductivities in vp), one for the signal frequency (vs), and one for the idler frequency (vi). These nonlinear currents are coupled via the optical fields of the interacting modes, as described by the following equationsIn the nonlinear simulations, three nonlinear surface currents are defined in the Comsol software, namely, one for the pump frequency ((3) is the third-order bulk susceptibility and the thickness of graphene is assumed to be heff = 0.3 nm (Eα, α = p, s, i, are the amplitudes of the pump, signal, and idler, respectively. More details about the nonlinearity of magnetized graphene and the coupled-mode theory describing the FWM interaction of graphene edge modes can be found in the Supplementary Materials.Here, the third-order surface conductivity is defined as


Arterial blood gases revealed metabolic acidosis. Definitive diagnosis was by a positive real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens, and high-resolution computed tomography (HRCT) finding of new-onset ground-glass opacities on the very first day of admission that was the presenting day. The patient became unresponsive and died overnight. As numbers of COVID-19 show an uprise, this case highlights that IPF patients with relatively advanced age need to exercise extra caution because they are at high risk for developing overwhelming COVID-19-linked sepsis, which may be fatal.The new disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was dubbed coronavirus disease 2019 (COVID-19) by the World Health Organization and declared a pandemic. Initially thought to be a pathogen that primarily attacks the lungs, SARS-CoV-2 has turned out to be a much more formidable foe impacting almost every organ and system aggressively. I report the case of a 60-year-old man who came to the ED due to symptoms of high fever, headache, mild confusion, dry cough and exacerbated dyspnea since the last 24 hours. He had a history of idiopathic pulmonary fibrosis (IPF) and was undergoing treatment with antifibrotic medication. Apart from IPF, he had no other comorbid. He acquired SARS-CoV-2 infection by close contact and infection deteriorated into pneumonia and septic shock. Complete blood count showed white blood cells at 3.3×10 Idiopathic pulmonary fibrosis (IPF) is a chronic fibrosing interstitial lung disease (ILD). The precise etiology of IPF is unclear although risk factors include old age and cigarette smoking, the onset is insidious and the prognosis is poor ,2.A new disease broke out in Wuhan, China in December 2019 as a cluster of pneumonia cases with etiology unknown . As moreHere I describe a case of an old man with preexisting IPF and laboratory-confirmed SARS-CoV-2 by real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR), who presented acutely with rapid progression (within hours) to septic shock.A 60-year-old man was brought to the ED with a one-day history of high fever, headache, mild confusion, dry cough, and increasing shortness of breath.2) above 90% and pirfenidone therapy, and had adhered to his medical regime. Apart from that, he was taking no other medications. He had smoked one pack of cigarettes daily for 15 years and quit 20 years ago. The patient worked as an investment banker and did not use alcohol or illicit drugs. There was no exposure to an inciting agent . He had not traveled recently, but was caring for his wife since four days who had tested positive for COVID-19. His last high-resolution computed tomography (HRCT) done a week before presentation has been included for analysis; a definite usual interstitial pneumonia pattern on this HRCT affirmed IPF  was already negative. His C-reactive protein was 55.9 mg/L, ferritin was 1480 ng/mL , and lactate dehydrogenase was 443 U/L . Coagulation studies revealed a prothrombin time (PT) of 23 sec, activated partial thromboplastin time (aPTT) of 53 sec, and D-dimer level of 2.1 μg/dL . Blood count, serum chemistry and liver function study is given in Table Arterial blood gas status six hours into admission is given in Table 2 on pulse oximeter was 86%. The patient was put on high flow oxygen, and remained on double inotropic support and Inj dopamine at 3 µg/kg/min. But despite all efforts, he collapsed of overwhelming infection. The emergency medical team found the patient unresponsive with no pulse.On the night following admission, his hemodynamic status deteriorated rapidly. Blood pressure fell to 50/20 mmHg despite receiving IV fluids. The venous access sites were oozing blood. Urine drainage from the Foley catheter was <20 mL/hr. GCS fell to 4/15. SpOThis patient's high fever, lymphocytopenia are indicative of SARS-CoV-2 pneumonia complicated by septic shock , the result of an overwhelming inflammatory response to infection. Severe sepsis is marked by organ dysfunction due to poor blood flow . His laboratory studies showed a consumptive coagulopathy , which, along with bleeding from the IV catheter site and elevated D-dimer, was likely due to DIC .IPF patients have an inexorable decline in respiratory reserve and lung function. Cytokines are implicated in the pathogenesis of IPF including initiation of a process called epithelial-mesenchymal transition, and SARS-CoV-2 itself causes further cytokine activation and inflammation thereby also justifying the use of steroids as a therapeutic option in virally driven hyperinflammation, but precisely why COVID-19-linked sepsis may be fatal . HRCT isAnswers to the following questions are being sought: the impact of COVID-19 on the rate of preexisting ILD progression, the mortality rate and predictors of mortality in patients with preexisting ILD and COVID-19 [In an analysis issued by the Chinese Center for Disease Control and Prevention using a cross-sectional study design, among the 44,672 confirmed cases of COVID-19, the case fatality rate was found to be elevated in those aged >/60 years, in males and among those with preexisting comorbids-10.5% for cardiovascular disease, 7.3% for diabetes, 6.3% for chronic respiratory disease, 6% for hypertension, and 5.6% for cancer. All 1023 deaths that occurred were critical cases; critical cases were identified as those that exhibited respiratory failure, septic shock, and/or multiple organ dysfunction . There iIn a retrospective study to determine the clinical outcome in 38 patients with a mean age of 68.3+/-11.5 years with IPF admitted to the Intensive Care Unit between 1995 and 2000, of the 37 patients whose data was available, nine patients (24%) developed sepsis with one patient each developing severe sepsis and septic shock. Thirty-five patients (95%) developed one or more organ failure. IPF was associated with poor short and long term prognosis . AlthougSARS-CoV-2 has a propensity to affect older adults with underlying IPF. IPF patients are at high risk for invasive and potentially fatal SARS-CoV-2 pneumonia. Manifestations of sepsis are more acute and severe in IPF patients. IPF patients be alerted to their increased susceptibility to fulminant SARS-CoV-2 infection and therefore they must go an extra mile to reduce potential exposure to COVID-19. Research is needed to elucidate further the clinical course, diagnostic criteria and outcomes of patients with concurrent COVID-19 and IPF.


ALS patients could be discriminated from PD and Ctrl with a sensitivity/specificity of 89 %/77 % and 89 %/83 %, respectively. Our findings demonstrate that TDP‐43 misfolding measured by the immuno‐infrared sensor technology has the potential to serve as a biomarker candidate for ALS.Pathologic alterations of Transactivation response DNA‐binding protein 43 kilo Dalton (TDP‐43) are a major hallmark of amyotrophic lateral sclerosis (ALS). In this pilot study, we analyzed the secondary structure distribution of TDP‐43 in cerebrospinal fluid of ALS patients ( Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with rapid loss of motor function. It leads to necessity of artificial nutrition, ventilation or results in death within few years after diagnosis. To date, one of the key challenges in ALS diagnostics is to exclude other mimicking diseases, which are assessed based on clinical and electrophysiological parameters, while disease‐specific diagnostic and prognostic biomarkers are still lacking. Recently, neurofilament light chain and phosphorylated neurofilament heavy chain gained attention as potential diagnostic and prognostic biomarkers for ALS.48‐scoreatdateofsamplecollectionduration between symptom onset and date of sample collection were collected . It represents a mixture of monoclonal recombinant antibodies against different epitopes of TDP‐43 to facilitate the complete extraction of total TDP‐43 from CSF. The immunogen used for antibody production corresponds to human TARDBP (aa 130‐275). Specific binding of human TDP‐43 was further analyzed by siRNA mediated knockdown of TDP‐43 and antibody performance was evaluated by western blot using recombinant TDP‐43 as shown in the manufacturer´s description . Instrumentation and data preprocessing comprising elimination of spectral contributions of water vapor were described previously in great detail and applied in the present study.Briefly, highly specific and sensitive capture antibodies are covalently attached to the sensor surface, followed by surface inertization via casein blocking solution to avoid unspecific binding and to solely extract the all isoforms of the biomarker fraction from CSF. Unspecifically bound proteins are removed from the sensor surface by excessive rinsing with buffer. Thus, only the desired biomarker is detected by the immuno‐infrared sensor. For TDP‐43 extraction we used 10 µg/mL recombinant oligoclonal TDP‐43 antibody  dissolved in phosphate buffer (50 mmol/L Na−1), receiver operating characteristic (ROC) analyses including calculation of the area under curve (AUC) were performed 5 times with different subsets comprising five ALS cases versus five PD subjects and their corresponding amide I maximum values and the same procedure with ALS versus Ctrl. Analyses revealed a mean threshold at 1643 cm−1, whereas lower values were indicative for TDP‐43 misfolding, which resulted in best discrimination accuracy with highest sensitivity and specificity. This threshold was set as discriminating threshold for analyzing the whole study group. Data were analyzed using the software Origin2019 by OriginLab (Software version 9.60).A Grubbs test was carried out before the data analysis to exclude outliers, which, however, were not identified. A Shapiro–Wilk test was used as statistical significance test to evaluate the sensor read‐out values (distribution of the amide I maximum frequency) for normal distribution. Thus, nonparametric Mann–Whitney U‐tests were performed to calculate significant group differences between the three diagnostic groups. The chi‐squared test was used for a comparison of gender differences. Spearman rank correlation coefficient was used to examine correlations between clinical characteristics and TDP‐43 misfolding. To determine the decisive diagnostic threshold for group differentiation . The ALS female ratio (61%) versus PD (33%) was significantly different (P = 0.09), but there was no significant difference between ALS versus Ctrl . We identified a weak correlation of the CSF‐to‐serum albumin concentration quotients  with the amide I maximum positions in ALS  and Ctrl , but not within the PD group . The average disease duration of ALS patients was 1.5 years and mean ALSFRS‐R score was 38 points at the time point of examination. 25 ALS patients had a spinal and 11 patients showed a bulbar disease onset  compared to PD subjects (1651 ± 7.7 cm−1 SD) and Ctrl (1646 ± 5.5 cm−1 SD), suggesting misfolding of TDP‐43 in ALS cases . To determine the diagnostic potential of TDP‐43 misfolding for differentiation of ALS versus PD and ALS versus Ctrl, we performed a ROC analysis on amide I maximum data resulting in an AUC of 0.85 (95%‐CL 0.75–0.95) for ALS versus PD and an AUC of 0.93 (95%‐CL 0.87–0.99) for ALS versus Ctrl. The threshold at 1643 cm−1 revealed a sensitivity of 89 % and a specificity of 77 % for the comparison of ALS versus PD and 89% Sensitivity and 83% Specificity for ALS versus Ctrl  with ALSFRS‐R slope ≥ 0.5 points/month showed significantly lower amide I maximum frequencies compared to slower progressive patients (n = 19) with ALSFRS‐R slope < 0.5 points/month (P < 0.05)   Fig. . Importa37) Fig. .In this pilot study, we investigated whether the secondary structure distribution of TDP‐43 is a potential biomarker candidate for ALS. The presence of TDP‐43 protein in human CSF measured by standard immunoassays was already shown in different studies.Our study revealed a significant increase of TDP‐43 protein conversion to β‐sheet enriched structures in CSF samples from ALS cases as compared to PD and Ctrl. Tests for diagnostic accuracy using a simple discriminative threshold resulted in a sensitivity of 89 % and a specificity of 77 % for TDP‐43 misfolding in case of ALS versus PD and 89% and 83% for ALS versus Others. Furthermore, ALS patients with clinically faster progression and patients in more progressed disease stages showed higher β‐sheet content of TDP‐43. We observed weak correlation of the Qalb and amide I maximum position for ALS and Ctrl, but not for PD. We suggest no direct effect of elevated albumin levels on our measurements, because unspecific binding of albumin would rather lead to higher amide I frequencies, since it consists primarily of helical structures and western blot analyses excluded unspecific binding of albumin. Therefore, a higher number of patient examinations should clarify this point.Moreover no specific binding of the antibody was achieved in CSF as evaluated by western blot. This was most likely due to the low levels of TDP‐43 in CSF, as shown in other studies.In conclusion, we present for the first time a TDP‐43 structure‐based biomarker for ALS, which should be validated in larger studies.L.T. and K.G. contributed to conceptualization and supervision. L.B., R.Gü., A.N., L.T., and K.G. contributed to methodology. L.B., R.Gü., A.N., L.T., and K.G. contributed to validation. L.B., R.Gü., and L.T. contributed to formal analysis. L.B., R.Gü., J.C.K., P.L., S.K., T.H., A.‐S.B., L.T., and K.G. contributed to investigation. L.B. and R.Gü. contributed to writing—original draft preparation. J.C.K., P.L., S.K., T.H., A.H., R. Go., A.N., L.T. and K.G. contributed to writing—review and editing. L. B. and L.T. contributed to project administration. All authors have read and agreed to the published version of the manuscript.P.L and L.T. are inventors on a patent for the use of Fasudil for the treatment of Amyotrophic lateral sclerosis . All other authors declare that there are no conflicts of interest.


Humidity detection range is an important indicator for measuring the performance of humidity sensors, but semiconductor humidity sensors often face the problems of narrow detection ranges and insufficient detection sensitivities. In this paper, a magnesium oxide (MgO) humidity sensor based on micro-arc oxidation (MAO) technology was designed to solve these problems by simultaneously using impedance and capacitance as the response signals, as well as by normalizing the output of the two signals. The experimental results showed that the average output of the micro-arc MgO ceramic film, with impedance as the response signal, could reach 150 in the low relative humidity(RH) range (11.3–67% RH), which was much higher than its sensitivity in the high humidity range (< 1), and the film showed fast response (13 s) and recovery (61 s). Under high humidity conditions (67–97.3% RH), with capacitance as the response signal, the output of the micro-arc MgO was as high as 120. Therefore, the micro-arc MgO humidity sensor with impedance, and the sensor with capacitance as the response signal, demonstrated good stability in low humidity and in high humidity environments, respectively, indicating that the method of selecting appropriate response signals for different humidity environments can be applied to extend the humidity detection range of sensing material, and to improve the humidity detection capability of a sensor. Humidity sensors have been widely used in various fields of human production and life, including weather forecasting, health care, and food processing ,3,4,5,6.Micro-arc oxidation (MAO) is a new technology to directly grow ceramic layers in situ on the surface of non-ferrous metals. This is done by placing a valve metal  in an aqueous electrolyte solution, and using electrochemical methods to generate spark discharge points in the surface micropores of the material, which is a method for generating oxides under the influence of thermochemistry, plasma chemistry, and electrochemistry. Technologies like this have the advantages of easy operation, environmental protection, and high efficiency ,17. MeanTo this end, this paper is devoted to the use of MAO to grow MgO film layers in situ on the surface of Mg plates to produce humidity sensing material. The microstructure and composition of the oxide layer were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The phase composition of the oxide layer was analyzed by X-ray diffraction (XRD). At the same time, impedance and capacitance were selected as the response signals to detect the humidity sensing performance of the film layer. The experimental results showed that the micro-arc MgO film with a porous structure on the surface had a large specific surface area. In different humidity environments, the micro-arc MgO film layer with impedance and capacitance as the response signals showed a major difference in output, indicating that the method of selecting appropriate response signals for different humidity conditions could be used to extend the humidity detection range of sensing material.(a)First, a 20 × 20 × 5 mm magnesium plate sample was cut out (purity > 99.5%). Sandpaper (400 # → 600 # → 800 #) was used to grind and remove oil (10% NaOH solution), then the magnesium plate was rinsed with deionized water and air-dried for later use.(b)2SiO3 solution using deionized water was prepared, and then NaOH powder was added to adjust the pH of the electrolyte to 13.A 10 g/L Na(c)The sample was hung on the electrode and immersed into the electrolyte. The anode was a magnesium plate and the cathode was a stainless steel electrolytic cell.(d)The power supply parameters were adjusted. The average current density was 4A/cm2, the duty cycle was 35%, the frequency was 550 Hz, the temperature of the electrolyte was maintained at 10–40 °C, and the oxidation time was 20 min. A circulating cooling device was used to keep the temperature of the configured electrolyte at 10–40 °C.(e)After oxidation, the micro-arc MgO plate was rinsed thoroughly with deionized water and dried in hot air.(f)A 200 # interdigital electrode screen plate was designed and purchased. The test piece was placed under the mesh, and the prepared conductive silver paste was uniformly printed on the micro-arc oxidation plate through the screen hole by using a scraper.(g)After the printing was completed, the MAO plate was held at 80 °C for 1 h to ensure that the silver paste was completely cured to fabricate a micro-arc MgO humidity sensor.The specific manufacturing steps (as shown in As shown in Capacitance testing was performed using an LCR bridge tester (VC4090A)  at an operating frequency of 1 kHz. The entire device could continuously change the humidity in the test environment, which was mainly used to test the change in the two response signals (impedance and capacitance) of the sensor with humidity.3COOK (22.5% RH), MgCl2 (32.8% RH), K2CO3 (43.2% RH), NaBr (57.6% RH), NaCl (75.3% RH), KCl (84.2% RH), and K2SO4 (97.3% RH) of 25 °C saturated solution in order to obtain a stable humidity environment [In addition, this paper configured LiCl (11.3% RH), CHironment . This paThe surface morphology and microstructure of the micro-arc MgO film layer were characterized by SEM, as shown in The surface and cross section of the micro-arc MgO film layer were shown at different magnifications. The thickness of the micro-arc oxide film was about 32 μm, which had good continuity, while the surface had a large number of abnormal pores with a diameter of 4–8 μm. This microporous structure allowed the micro-arc MgO film layer to have a larger surface area, providing more adsorption sites and reaction channels for water molecules, which was helpful for enhancing the moisture-sensing properties of the material. The XRD measurement of the micro-arc MgO film layer was performed with an X-ray diffractometer. The XRD results  showed tR and SC:At the 1 kHz operating frequency, the impedance and capacitance of the film in different humidity environments were measured separately to investigate the effects of different response signals on the humidity sensing performance of micro-arc MgO. As shown in R and SC denote the output result of micro-arc MgO when impedance and capacitance are used as response signals. RRH and CRH are the impedance and capacitance of micro-arc MgO in various humidity environments, respectively. R97.3% and C11.3% represent the impedance and capacitance values of the micro-arc MgO at 97.3% RH and 11.3% RH, respectively.S2 is 0.9724 and 0.9977, respectively, indicating a good curve fitting. 2+) had greater electron affinity than the internal positive ions, the surface acceptor level occurred slightly below the conduction band bottom [2−) on the surface had greater electron repellency than the internal negative ion, so the surface donor level appeared slightly above the valence band. Before the adsorption of water molecules by micro-arc MgO, the density of surface states of donors was significantly higher than that of acceptor surface states, which led to the downward bending of the energy band at the surface, forming a hole depletion layer, and exhibiting high impedance [2− on the surface of the material, which caused the density of the surface donor state to decrease. The originally trapped holes were released, while the carrier concentration rose, showing a decrease in resistance [MgO is a p-type semiconductor, which has a larger band gap (7.8 eV) than other metal oxides. Since the surface positive ions  and hydrogen (H+) [As shown in gen (H+) :(3)H2O⇔H− was chemically adsorbed on the surface of the membrane and was connected to the metal cation (Mg2+) by hydrogen bonding, so that the chemically adsorbed aqueous layer was firmly bonded to the surface of the sensing membrane, which was difficult to remove. In a low humidity environment, discontinuous water molecules were mainly physically adsorbed above the chemisorbed layer to form a first physically adsorbed aqueous layer. However, because hydrogen bonding limited the free movement of water molecules, protons did not have a continuous jump path, thus at this stage, the capacitance increased slowly with increasing RH. As RH continued to increase to higher levels, multiple continuous water molecules appeared on the surface of the membrane layer, which made the transfer of hydronium ions (H3O+) easier than before. According to the Grotthuss chain reaction [OHreaction ,41, thisPhysically adsorbed water molecules would penetrate into the pores of the membrane layer, further improving the sensor response. All of these factors caused a sudden increase in capacitance, so there was a large slope in the relationship between capacitance and RH. Meanwhile, according to this mechanism, three adsorbing steps, including the generation of first chemisorbed layer, first physisorbed layer, and multi-physisorbed layer, exist in adsorption process. Each process will continuously increase the capacitance of the sensor. Compared to a resistive humidity sensor, the response time of a micro-arc MgO humidity sensor with a capacitance as a response signal is longer.For the first time, we used MAO to prepare a MgO ceramic moisture-sensitive film with a large number of micropores appearing on the surface, and we used impedance and capacitance as the response signals. The experimental results showed that in the low humidity range (11.3–67%RH) with impedance as the response signal, the average output was up to 150, with faster response (13 s) and recovery (61 s). Under the high humidity conditions (67–97.3%), with capacitance as the response signal, the average output of the micro-arc MgO humidity sensor was as high as 120. Based on the above experimental results, we can increase the humidity detection range of the sensing material by selecting an appropriate response signal for different humidity conditions, and then develop a humidity sensor with fast response and recovery, small hysteresis, and high response.


General knowledge varies from one country to another; therefore, the mere translation of knowledge-based experimental tools from one language to another is usually not enough. This is one of the conclusions that can be extracted from the results of the Program for International Student Assessment (PISA), a measure of the knowledge achieved by 15-year-olds. This assessment provides each participating country 79 in 2018) with a comparative measure of the efficiency of their educational programs within an internationally agreed common framework and allows them to identify the most effective educational practices as well as gaps in curricula. Over the years, this periodic measure has reflected clear differences between countries in different areas of knowledge. The PISA program assesses mathematics, sciences, and reading, designed as an indicator of “how well the students master key subjects in order to be prepared for real-life situations in the adult world” . Russian is one of the most spoken languages in the world, the largest native language in Europe, one of the six official languages of the UN, and the second most used languages on the Internet globallyMetacognitive evaluations such as retrospective confidence judgments provide valuable information about the selection of a specific answer. Retrospective confidence is the subjective assessment of how correct the selected answer is  recruited on social media took part in the experiment for a small monetary compensation (250 rubles per hour of experiment ~ 3.5 USD).One hundred three native Russian speaking participants : most of them were completing their university studies , close to the 30% already had a university degree , and a very small amount only had completed high school . In Russia, it is compulsory to pass the Unified State Exam to get the diploma after finishing school; therefore, we can assure that all of our participants had a similar minimum of general knowledge.M = 7.76 (SD = 1.38), and none of them reported to be under medical treatment.We included two more additional questions about time of sleep last night and medication intake to assure the optimal state of participants to complete this long experiment. Five participants did not report the number of hours of sleep; for those who did, the mean average was https://iq2u.ru/, which is directly oriented to students and professors and contains exemplars of the questions used in the Unified State Exam. These exams are compulsory in Russia either to get the high-school diploma or access to university studies (https://en.wikipedia.org/wiki/Unified_State_Exam). We also selected some other questions from https://baza-otvetov.ru/, which is a website for people interested in solving quizzes. For each question, participants had to select one alternative and rate the confidence they had in its correctness on an 11-point confidence scale ranging in 10% steps from 0%  to 100% . Dependent variables were (1) accuracy and (2) confidence in the correctness of the selected answer.Five hundred two multiple-choice GKQs were used in the experiment see . Five huThe experiment was programmed using SR Research Experiment Builder . The experiment consisted of one training session with two questions, and 10 experimental blocks with 50 questions each. The order of appearance of the questions in the experimental blocks, the blocks, as well as the placement on the screen of the alternatives was fully counterbalanced for each participant. The training questions were the same for all participants and their answers were not included into the analysis.Participants were tested individually on a computer. First, participants read and signed the informed consent form and completed the demographic data along with questions about the number of hours of sleep they got the previous night, level of education, and medication intake. They were then given instructions explaining every phase of the experiment and presented with two training questions. Then, the main experimental part started. In each trial see , particiOut of the 500 multiple-choice GKQs, all participants consistently chose the correct answer for 8 of them. In addition, there were 7 questions more for the group of females  and 12 for the group of males  for which participants of each gender always selected the correct choice. There were 19 questions in the entire sample for which participants only selected one of two alternatives (the other two were never selected), and 66 questions for which one of the alternatives was never chosen. All of the questions for which one, two, or three alternatives were never selected are indicated in t test, and Cohen's d was used to estimate effect size. There were no differences between female and male participants considering all the questions or when splitting them by topic.Recognition tests are easier to solve than other memory tests such as cued recall or free recall because they are based on familiarity Tulving, . This fat test, Cohen's d for effect size, and Bonferroni correction for multiple comparisons when appropriate. We found that males assigned significantly higher confidence to the correctness of their answers to questions about History and Geography than females did. No other differences were found.x-axis represents confidence and the y-axis represents accuracy, is the diagonal and represents the point in which accuracy and confidence are perfectly matched . There is “overconfidence” when the confidence rating is higher than the accuracy obtained  and “underconfidence” when the pattern is reversed, that is, lower confidence rating than the accuracy obtained .Confidence–accuracy calibration curves show the correspondence between answer accuracy (objective measure) and confidence (subjective measure) with which answers are given in a test  and male , t(44) = 0.209, p = 0.835. Also, both Cs were significantly different from 0: for females t(44) = 10.156, p < 0.001, and for males, t(44) = 9.950, p < 0.001.We computed the Calibration index  disregards all cultural background, which has in fact been shown to affect problem solving (Chen et al., The multiple-choice format with four options made the present battery of questions suitable for a wide variety of experiments to be performed in Russian within a sample with similar characteristics. Moreover, the additional information obtained from the participants' subjective experience will enable experimenters to more carefully select questions to guide their experiments. All of our participants had a high-school diploma, which, for Russian citizens, means that they completed successfully the Unified State Exam, covering a range of subjects (Francesconi et al., Finally, in this study, we used new questions that were not previously used in other published studies. This somewhat complicated cross-cultural comparison of our results with other samples obtained in other languages and cultures. A follow-up step of this research line could be to improve this database incorporating questions used in other studies (e.g., Tauber et al., All datasets generated for this study are included in the article/The studies involving human participants were reviewed and approved by Ethics committee of National Research University-Higher School of Economics. The participants provided their written informed consent to participate in this study.BM-L, OZ, MA, and YS contributed in the design. MA collected the data. OZ and BM-L performed the data analysis. All authors contributed in writing of the manuscript.The materials of this experiment can be found in the The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The effect of the parameters of this method on the structure of transferred graphene islands is investigated. The relevance of reducing the distance between irradiating and receiving substrates for the transfer of free-lying graphene is demonstrated. The reasons for the damage to the integrity of the carbon film observed in the experiments are discussed. The preservation of the original crystal structure of transferred graphene is confirmed by Raman spectroscopy.The patterning and transfer of a two-dimensional graphene film without damaging its original structure is an urgent and difficult task. For this purpose, we propose the use of the blister-based laser-induced forward transfer (BB-LIFT), which has proven itself in the transfer of such delicate materials. The ease of implementation of laser techniques reduces the number of intermediate manipulations with a graphene film, increasing its safety. The work demonstrates the promise of BB-LIFT of single-layer graphene from a metal surface to a SiO The use of graphene in optics and electronics requires transferring the monolayer carbon material to an arbitrary, usually dielectric, substrate and forming the necessary pattern from it; for example, the channel of the transistor ,2. The sHere, we report on the results of the BB-LIFT of the fragments of pure graphene film. The effect of the thickness of the absorbing metal layer and the gap between the donor and acceptor substrates on the quality of the transfer is analyzed. Possible changes in the internal structure and morphology are controlled by Raman spectroscopy and scanning electron microscopy (SEM), respectively.−5 mbar by the heating aluminum foil in a molybdenum boat to 900 °C with a current passing through it. Then, a polycrystalline graphene film grown on copper foil by chemical vapor deposition (CVD) was transferred to the surface of the aluminum film by a standard wet method using PMMA as a supporting polymer, which was chemically removed after the transfer [Experimental samples, the so-called donors, were prepared in two stages. First, to absorb the energy of the pulsed laser radiation, an aluminum film was deposited on the surface of a polished quartz plate. The metal film deposition was performed in a vacuum chamber at a pressure of 10transfer ,21,22. T2) to cut out the central homogeneous part of the laser beam. In such a projection scheme, the image of the mask was reduced 20 times into a 60 × 60 μm2 spot. In our experiments, the laser fluence in the irradiated spot was varied discretely from 1.2 to 3 J/cm2.The BB-LIFT procedure applied to the donor sample containing a graphene film is illustrated in 2) surface layer were chosen as receiving substrates, the so-called acceptor, which made it possible to control the transfer of the graphene film on the substrate surface by optical methods [Silicon substrates with a 90 nm-thick silicon dioxide  and SEM . The surface morphology was also analyzed using an Axiotech 25HD optical microscope .2. In this case, the graphene film starts to transfer after the irradiation with a laser fluence exceeding the value of 1.2 ± 0.1 J/cm2. Therefore, the working range of the laser fluence changes from 0.2 ÷ 0.8 to 1.2 ÷ 2.8 J/cm2. The distance between the donor and acceptor substrates remains the same as in previous experiments [2, a noticeable change in the amount of transferred material onto the acceptor surface is observed, which is associated with the beginning of the ablative metal transfer. It is indicated by the metal rupture that can be observed in In this work, we increase the thickness of absorbing aluminum film from 420 to 1900 nm, which leads to an increase in its ablation threshold from 0.8 ± 0.1 to 2.8 ± 0.2 J/cmeriments . When th2 hybridization) of single-layer graphene if the laser fluence exceeds the value of 1.2 ± 0.1 J/cm2. −1 (peak G) and 2670 cm−1 (peak 2D) are detected for the original film and transferred flakes. The width of the 2D peak is about 32 cm−1 in almost all regions, which indicates the transfer of single-layer graphene [−1 corresponds to the presence of defects in the carbon material. To analyze the defect formation in the transferred graphene material, we calculate the Id/Ig ratio of the intensities of the D and G peaks in the initial film and transferred graphene fragments. After the transfer, the Id/Ig ratio increases from 0.07 to a maximum of 0.18, which corresponds to a change in the distance between defects from 38 to 24 nm [The Raman spectroscopy analysis of islands of the transferred material shows that graphene is transferred by separate micron-sized flakes to the acceptor substrate with the preservation of the initial crystal structure (spgraphene . In the graphene . The incto 24 nm .2, which was not previously observed in experiments with a thin metal film at a fluence value reaching the threshold of metal ablation [The Raman spectroscopy analysis of the donor surface in the irradiated areas after the transfer shows a complete absence of graphene in them at a laser fluence higher than 1.6 ± 0.1 J/cmablation . Thus, a2, respectively. The increase in ratio corresponds to a decrease in the distance between defects from 38 to 32 and 26 nm, respectively.An analysis of the material transferred in the scheme without a gap between the substrates by Raman spectroscopy  shows th2, most promising for the imprint quality (2 [For a more detailed comparison and analysis of the morphology of the transferred graphene in the two considered configurations of the laser transfer scheme, we used SEM images.  quality . For com quality . In the ality (2  have shoality (2  or superality (2 .The BB-LIFT of the crumpled fragments of graphene film was demonstrated. The increase in the thickness of the absorbing metal layer allowed us to transfer the graphene material from all over the irradiated spot of the donor onto the acceptor substrate without signs of the metal. Reducing the gap between the substrates to a value of zero results in matching the patterns on the acceptor to the shape of the laser spot. Raman spectroscopy indicates the preservation of the initial structure of graphene after the LIFT, with a slight change in the distance between defects from 38 to 32 nm at the optimal conditions of the transfer. The SEM analysis shows the transfer of crumpling micrometer-scale islands of the graphene film. Therefore, the applied technique requires further optimization of the transfer conditions so as to print a continuous pixel from a graphene film.


Furthermore, the carrier mobility of the camphor-based CVD bilayer graphene at room temperature is 1.8 × 103 cm2/V·s. Due to the incorporation of camphor-based CVD graphene, the graphene/p-Si Schottky junctions show a good rectification property (rectification ratio of ~110 at ± 2 V) and good performance as a self-powered (under zero bias) photodetector from UV to LWNIR. The photocurrent to dark current ratio (PDCR) value is up to 230 at 0 V under white light illumination, and the detectivity (D*) is 8 × 1012 cmHz1/2/W at 560 nm. Furthermore, the photodetector (PD) response/decay time  is ~118/120 μs. These results support the camphor-based CVD bilayer graphene/Si Schottky PDs for use in self-powered and ultra-broadband light detection in the future.This work demonstrates a self-powered and broadband photodetector using a heterojunction formed by camphor-based chemical vaper deposition (CVD) bilayer graphene on p-Si substrates. Here, graphene/p-Si heterostructures and graphene layers serve as ultra-shallow junctions for UV absorption and zero bandgap junction materials (<Si bandgap (1.1 eV)) for long-wave near-infrared (LWNIR) absorption, respectively. According to the Raman spectra and large-area (16 × 16 μm Furtherformance . Under zf the PD ,51. CompHz1/2/W)  and the I-V characteristics of camphor-based CVD graphene/p-Si Schottky PDs [Fg) is lower than the Si Fermi energy (EFSi), leading to the SBH (qΦB) lowering, as shown in Fg is higher than EFSi , resulting in the increase in SBH. Moreover, the barrier height (qΦbi) of the hole from p-Si to graphene will be reduced gradually with an increasing forward bias, leading to a higher dark current. Therefore, the dark current under a low reverse bias (from 0 V to −2 V) is much lower than under a low forward bias (form 0 V to +2 V), as shown in As shown in ttky PDs ,55,56,57To highlight the stable and high-speed photoresponse properties of the camphor-based CVD bilayer graphene/p-Si Schottky PDs, the time-resolved measurements were performed under a 3 V bias, as shown in 2) Raman mapping images, and Hall measurements could reveal that our camphor-based CVD graphene has low defects, >95% coverage bilayer structures, a high-uniformity, and a high carrier mobility (1.8 × 103 cm2/V·s). By employing camphor-based CVD bilayer graphene/p-Si Schottky junctions, our PDs also show a high rectification ratio value (~110 at ±2 V) and high photo-sensing performances (such as an ultra-broadband (from UV to LWNIR) photoresponsivity (under zero bias), a high PDCR value (up to 230 at 0 V), and high detectivity (D*) (8 × 1012 cmHz1/2/W at 560 nm)). In addition, the operation speed of PD was revealed by the rise time and fall time as fast as 118 and 120 μs, respectively. This work demonstrates that the low-cost camphor-based CVD bilayer graphene incorporating p-Si holds promise for practical applications in the new generation of self-powered and ultra-broadband photon detection.In summary, a self-powered and broadband PD using a camphor-based CVD bilayer graphene/p-Si heterojunction was fabricated. Here, graphene layers could unite with p-Si to form ultra-shallow Schottky junctions for absorbing UV light effectively and, at the same time, graphene layers with zero bandgap could also provide a higher LWNIR absorption than Si. Raman spectra analyses, large-area (16 × 16 μm