In this study, the HIV-1 P18I10 CTL peptide derived from the V3 loop of HIV-1 gp120 and the T20 anti-fusion peptide of HIV-1 gp41 were inserted into the HPV16 L1 capsid protein to construct chimeric HPV:HIV (L1:P18I10 and L1:T20) VLPs by using the mammalian cell expression system. The HPV:HIV VLPs were purified by chromatography. We demonstrated that the insertion of P18I10 or T20 peptides into the DE loop of HPV16 L1 capsid proteins did not affect in vitro stability, self-assembly and morphology of chimeric HPV:HIV VLPs. Importantly, it did not interfere either with the HIV-1 antibody reactivity targeting sequential and conformational P18I10 and T20 peptides presented on chimeric HPV:HIV VLPs or with the induction of HPV16 L1-specific antibodies in vivo. We observed that chimeric L1:P18I10/L1:T20 VLPs vaccines could induce HPV16- but weak HIV-1-specific antibody responses and elicited HPV16- and HIV-1-specific T-cell responses in BALB/c mice. Moreover, could be a potential booster to increase HIV-specific cellular responses in the heterologous immunization after priming with rBCG.HIVA vaccine. This research work would contribute a step towards the development of the novel chimeric HPV:HIV VLP-based vaccine platform for controlling HPV16 and HIV-1 infection, which is urgently needed in developing and industrialized countries. Human immunodeficiency virus-1 (HIV-1), which causes acquired immunodeficiency syndrome (AIDS), was discovered in the early 1980s, and since then it has become a global epidemic . In spitIn our previous review paper publication regarding design concepts of virus-like particle (VLP)-based HIV-1 vaccines, we mentioned that non-enveloped VLPs, such as papillomavirus VLPs, could play a functional role as delivery vectors to present HIV-1 CTL or neutralizing antibody epitopes ,16. ThisIn this study, we aimed at developing a chimeric VLP-based HPV:HIV vaccine by using human 293F cells, a well-established mammalian cell expression system. The HPV 16 L1 protein acted as the structural vaccine scaffold, and the P18I10 and T20 peptides were selected as HIV-1 immunogens and inserted into the DE loop of HPV16 L1 protein. The immunodominant P18I10 CTL epitope comprising 10 amino acids (residues 311–320: RGPGRAFVTI) is derived from the third variable domain (V3) of the HIV-1 envelope glycoprotein gp120. The P18I10 peptide has been identified as a H-2Dd-restricted MHC class-I molecule to induce cytotoxic T lymphocytes (CTL) responses ,26. The Mycobacterium bovis Bacillus Calmette-Guérin (rBCG) expressing HIV-1 Gag prime and HIV-1 Gag VLP boost may contribute to enhance T-cell immunity [Over the past decade, many different prime-boost formats of VLP-based HIV-1 vaccine have been tested . Althougimmunity ,30. In oimmunity ,32,33. Timmunity . TherefoIn this study, the chimeric HPV:HIV (L1:P18I10 and L1:T20) immunogens were designed and produced by using 293F expression system. The chimeric L1:P18I10 and L1:T20 protein expression was confirmed by immunostaining. The HPV:HIV VLPs were subsequently purified by a 3-step chromatographic method, including cation (CEC), size exclusion (SEC) and heparin affinity (H-AC) chromatography. Then, the in vitro stability, in vitro self-assembly and morphology of purified HPV:HIV VLPs were confirmed by non-reducing SDS-PAGE, molecular mass assay and transmission electron microscopy (TEM), respectively. The sequential and conformational P18I10 and T20 peptides presented on chimeric HPV:HIV VLPs were further characterized by anti-HIV-1 gp120 V3 and 2F5 monoclonal antibodies in vitro by using Western blot and indirect ELISA assay. Finally, the immunogenicity of HPV:HIV VLPs was assessed in BALB/c mice model. We demonstrated that chimeric L1:P18I10 and L1:T20 VLP-based vaccines could induce HPV16- and HIV-1-specific antibody responses and chimeric L1:P18I10 VLPs could induce HPV16- and HIV-1-specific T-cell responses in BALB/c mice. Because the development and manufacturing of an immunogenic HPV:HIV vaccine is still unachievable, this study provided a baseline strategy that may be worth supporting the global efforts to develop novel chimeric VLP-based vaccines for controlling HPV and HIV-1 infections.E.coli-mycobacteriol integrative shuttle vector p2auxo.int. The construction of E. coli/mycobacterial vector expressing HIVA antigen was previously described [2auxo.int was diluted in PBS-Tween20 to 2 × 107 cfu/mL, sonicated to disrupt bacterial clumps and inoculated into the rear food pad or BALB/c mice .Recombinant BCG expressing HIVA immunogen was previously constructed using the escribed ,32,33. BE. coli, M151GlyA , provided by Dr. Pau Ferrer, were cultured in minimal M9-derivative medium , supplemented with glycine (70 μg/mL). The E. coli M151Gly cells were transformed with the p2auxo.HIVA plasmids by electroporation. For this, the E. coli cultures were grown to an optical density of 0.9 at 600 nm, transformed using a Bio-Rad gene pulser electroporator at 2.5 kV, 25 μF, and 200 Ω. The transformed cells were subsequently cultured on M9-D agar plates  without glycine supplementation for selection or with glycine supplementation as a control. The lysine auxotrophic BCG strain, BCGΔlys, kindly provided by W.R. Jacobs Jr., B.R. Bloom, and T. Hsu was transformed with p2auxo.HIVAint plasmid DNA by electroporation. The mycobacteria were cultured in Middlebrook 7H9 broth medium or on Middlebrook agar 7H10 medium supplemented with albumin-dextrose-catalase  containing 0.05% Tween 80. L-lysine monohydrochloride  was dissolved in distilled water and used as a supplement at a final concentration of 40 μg/mL. For transformation, BCG was cultured to an optical density of 1.5 at 600 nm, transformed using a Bio-Rad gene pulser electroporator at 2.5 kV, 25 μF, and 1000 Ω. The transformants were then cultured on ADC-supplemented Middlebrook agar 7H10 medium containing 0.05% Tween 80 without lysine supplementation.Cells of the glycine auxotrophic strain of 2 on an orbital shaker platform rotating at 125 rpm.The 293F cells (gibco), derived from human embryonic kidney (HEK) 293 cells, were cultured in FreeStyle 293 expression medium (gibco) supplemented with 5 mL/L of penicillin-streptomycin (gibco) and incubated in a 37 °C incubator containing a humidified atmosphere of 5% COE. coli DH5α competent cells (Invitrogen) for amplification and extracted by using plasmid Maxi kits . The 293F cells were cultured with 30mL FreeStyle 293 expression medium in a 125mL Erlenmeyer flask  to a density of 1.0 × 106/mL and transiently transfected with L1:P18I10 or L1:T20 pDNAs using the branched polyethylenimine with a MW of 25 kDa (PEI-25K) (Polysciences) at an optimized ratio of DNA to PEI 1:3 (w/w) and DNA to culture medium 1:1 (w/v), according to manufacturer’s instructions [6 cells/mL with approximately 50% viability.The pCDNA3.1 construct contained L1:P18I10 or L1:T20 DNA coding sequences corresponding to chimeric L1:P18I10 and L1:T20 proteins, respectively. The HIV-1 P18I10 CTL peptide (RGPGRAFVTI) or T20 peptide (YTSLIHSLIEESQNQQEKNEQE LLELDKWASLWNWF) were inserted into the DE loop of HPV16 L1 capsid protein. The HPV16 L1 DE loop sequence encoding 130–136 amino acids was replaced with either P18I10I10 or T20 peptide. The L1:P18I10 or L1:T20 DNA coding sequences were modified with Kozak sequence, optimized with human codon, flanked by the restriction enzyme sites of HindIII and XbaI and cloned into pcDNA3.1(+) vector by using GeneArt gene synthesis services . The recombinant plasmid DNA (pDNA) was transformed into ructions . The 293The cells were permeabilized on the glass slide with 100% cold acetone. Subsequently, the fixed cells were probed with anti-HPV16 L1 antibody CAMVIR-1  and captured with anti-mouse IgG-FITC (Sigma). Immune-stained cell monolayers were thoroughly washed with PBS and covered with mounting medium with DAPI (Abcam). The immunofluorescence images were inspected under an inverted microscope at 40× magnification. Transfection efficiency was determined by the ratio of FITC (green)-positive cells to DAPI (blue)-stained cells.8 transfected 293F cells in a 125 mL Erlenmeyer flask (30 mL culture medium/flask) were collected by centrifugation at 1500 rpm for 5 min and washed twice with PBS. Cell pellets were resuspended in lysis buffer formulated with 1% Triton X-100, protease inhibitor (1:100) (Millipore) and Benzonase (25 U/mL) (Millipore). Cell lysates were clarified with 0.45 µm PVDF syringe filter (Millipore). The HPV:HIV (L1:P18I10 and L1:T20) VLP samples were serially purified using cation exchange , size exclusion  and affinity  chromatography. The chromatographic protocols were described in our previous studies [A total of 10 studies ,37 and f studies . The L1  studies .v/v) 2-mercaptoethanol (2-ME) and reacted at room temperature (RT) for 24 h. Samples were separated by 8–16% TGX stain-free protein gels (BIO-RAD). Then, the gels were transferred to PVDF membranes. The membranes were probed with the anti-HPV16 L1 CAMVIR-1 mAb at a dilution of 1:4000. After that, the membranes were incubated with anti-mouse IgG Peroxidase Conjugate  at a dilution of 1:4000. The signal was developed and visualized by chemoluminiscence using Western Blot ECL substrate kit . The blot images were acquired by using Odyssey Fc imaging system.The HPV16 L1, L1:P18I10 and L1:T20 VLPs were mixed with 2× Laemmli sample buffer (BIO-RAD) in the absence or presence of 5%  ultrafiltration devices (SARTORIUS). The HPV16 L1, L1:P18I10 and L1:T20 VLPs with 2-ME treatment were passed through 100 kDa MWCO ultrafiltration devices (Amicon). The retentates were reconstituted to the original volume and collected from the filter device sample reservoir, while the filtrates were collected at the bottom of the centrifuge tube. The L1 signal was measured by using dot blot probed with anti-HPV16 L1 mAb and detected by anti-mouse IgG-peroxidase conjugate (Sigma-Aldrich). Images were acquired using Odyssey Fc Imaging System at a chemiluminescence channel.After charging the carbon-coated copper grids (Sigma-Aldrich) under ultraviolet light for 5 min, commercial HPV16 L1 (Abcam), purified L1:P18I10 and L1:T20 VLPs equilibrated with 20 mM Tris-HCl  were absorbed on grids for 1 min and rinsed three times by miliQ water. The HPV:HIV VLPs were negative-stained with 2% uranyl acetate at pH 4.5 (Sigma-Aldrich) for 1 min. Excess staining agents were removed by Whatman qualitative filter paper (Sigma-Aldrich). Grids were placed in a dehumidifier chamber at least 2 h before observation. Images were acquired using a transmission electron microscope (Tecnai Spirit 120 kV) at magnification SA135K (100 nm) and SA59000 (200 nm), respectively.Equal amounts (500 ng) of HPV16 L1 protein (Abcam), purified L1:P18I10 and L1:T20 VLPs were mixed with 2× Laemmli sample buffer containing 5% 2-ME and boiled at 95 °C for 5 min. Samples were separated by 8–16% TGX Stain-free protein gels and then transferred to a PVDF membrane  using a Semi-Dry transfer device (Bio-Rad). The membrane was blocked with 5% skim milk in TBST. Then, the membranes were probed with the anti-HPV16 L1 CAMVIR-1 mAb at a dilution of 1:4000, anti-HIV-1 gp120 V3 loop mAb  at a dilution of 1:40 and HIV1 gp41 (2F5) mAb  at a dilution of 1:4000, respectively. After that, the membranes were incubated with anti-mouse IgG Peroxidase Conjugate (Sigma-Aldrich) at a dilution of 1:4000. The Western ECL substrate kit (BIO-RAD) was used for signal development. The blot images were acquired by using Odyssey Fc imaging system at a chemiluminescence channel.n = 4 and female n = 4 per group). In groups A and B, BALB/c mice were immunized intramuscularly (i.m.) with 10 μg of L1:P18I10 or L1:T20 VLPs, respectively, by following a homologous prime-boost regime. In the group C, mice were inoculated with 106 cfu of BCG.HIVA2auxo.int intradermally  and boosted with 10 μg of L1:P18I10 VLPs intramuscularly. In the group D, positive control mice were inoculated with Gardasil-9 prime followed by Gardasil-9 boost intramuscularly with 10 μg of HPV16 L1 VLPs. In the group E, negative control mice were immunized twice with PBS buffer. The prime-boost interval was 2 weeks. Mice were sacrificed on day 28. Blood samples were collected from the heart of mice. Sera were recovered by centrifugation and stored at −20 °C for ELISA assay. Murine spleens were removed and pressed individually through a cell strainer  with a 5 mL syringe rubber plunger. Following the removal of red blood cells with ACK lysing buffer (Lonza), splenocytes were washed and resuspended in lymphocyte medium R10 , penicillin-streptomycin, 20 mM HEPES and 15 mM 2-ME) at a concentration of 2 × 107 cells/mL.This is a preliminary proof-of-concept study to demonstrate immunogenicity of HPV:HIV VLPs (L1:P18I10 and L1:T20 VLPs). The dose, administration route and prime-boost interval of our HPV:HIV VLPs referred to previous studies that immunized mice with bovine papillomavirus (BPV):HIV VLPs for inducing antibody responses . Purifie2SO4. The optical density (OD) of each well was measured and recorded at a wavelength of 450 nm by using EL × 800 absorbance microplate reader.To test the HPV16 L1- and HIV-1-specific antibodies binding to chimeric HPV:HIV VLP constructs in vitro, 50 µL of equal concentration (200 ng/mL) of recombinant HPV16 L1 protein , purified L1:P18I10 and L1:T20 VLPs in 50mM carbonate-bicarbonate buffer (pH = 9.6) (Sigma) were 2-fold serially diluted and coated onto the Maxisorb plates (Nunc). The plates were incubated at 4 °C overnight. Plates were blocked with the blocking buffer (5% skim milk in TBST) at 37 °C for at least 2 h. After wash twice with TBST, the VLP-coated plates were incubated with anti-HPV16 L1 CAMVIR-1 mAb at a dilution of 1:8000, 2F5 mAb  at a dilution of 1:8000 and anti-HIV-1 gp120 V3 loop mAb  at a dilution of 1:40 in blocking buffer, respectively, at 37 °C for 2 h. After washing three times with TBST, the plates were incubated with recombinant protein G peroxidase conjugate  at a dilution of 1:4000 in blocking buffer at 37 °C for 1 h. TMB was used to develop the enzyme-linked immunosorbent assay (ELISA) signal and stopped with 50 µL of 2M H2SO4. The OD of each well was measured at a wavelength of 450 nm by using EL × 800 absorbance microplate reader (Biotek).To measure the VLP-induced antibodies in BALB/c mice, the microtiter plates were coated with 50 µL of 2 µg/mL recombinant HPV16 L1 protein , HIV-1 P18I10 peptide , T20 peptide , respectively, with 50 mM carbonate-bicarbonate buffer (pH = 9.6). The plates were incubated at 4 °C overnight. Plates were blocked with the blocking buffer (5% skim milk in TBST) at 37 °C for at least 2 h. At the same time, sera collected from the group A-E immunized mice were diluted with 5% skim milk in TBST at a ratio of 1:50. After wash twice with TBST, the plates were incubated with the diluted sera at 37 °C for 2 h. After washing three times with TBST, the plates were added with recombinant protein G HRP conjugate at a dilution of 1:4000 in blocking buffer and incubated at 37 °C for 1 h. TMB was used to develop the ELISA signal and stopped with 50 µL of 2M H5 fresh splenocytes were added to each well. Subsequently, the cells from groups A and B were stimulated with 2 μg/mL of HPV16 L1 VLPs and HIV-1 P18I10 peptides, respectively. All the samples and controls were plated in duplicate wells. ELISpot assays were incubated for 16 h at 37 °C, 5% CO2. The plates were subsequently washed 5 × with PBS, incubated for 2 h with a biotinylated anti-IFN-γ monoclonal antibody (mAb) diluted in PBS 2% Fetal Calf Serum (FCS) to a final concentration of 2 µg/mL, washed 5 times in PBS, and incubated with the streptavidin-alkaline phosphatase conjugate in PBS 2% FCS. Then, plates were washed 5 times with PBS before incubating with 100 µL of 5-bromo-4-chloro-3-indolyl phosphate (BCIP)/nitro blue tetrazolium (NBT) substrate solution . After 5–10 min, the plates were washed with tap water, dried, and the resulting spots counted using an ELISPOT reader . For each animal, the mean of background responses was subtracted individually from all the wells to enable a comparison of the IFN-γ spot forming cells (SFC)/106 between groups. To define positive responses, a threshold was defined as at least five spots per well, and responses exceeding the mean number of spots in negative control wells plus three standard deviations of the negative control wells.The enzyme-linked immune absorbent spot (ELISpot) assay was performed using the commercial murine IFN-γ ELISpot kit , according to the manufacturer’s instructions. The ELISpot plates  were 70% EtOH treated and coated with purified anti-mouse interferon-γ (IFN-γ) capture monoclonal antibody diluted in phosphate-buffered saline (PBS) to a final concentration of 5 µg/mL at 4 °C overnight. Then, 2.5 × 10All statistical analysis was performed using Prism 6 GraphPad software . We used data from experiments carried out over 5 different ELISA plate coating concentration  of recombinant HPV16 L1 protein  and HPV:HIV VLPs. We collected data from 2 groups (HPV16 L1 and HPV:HIV VLPs) and collected three replicates for each coating concentration. The graph in Prism showed the data as a scatterplot showing coating concentration (ng/mL) on the X-axis and OD450 on the Y-axis. Since we hypothesized that our in vitro ELISA data is related in a linear pattern, we performed the linear regression analysis and compared the slopes of the two lines to confirm that data set-1 and data set-2 (antibody reactivity between HPV16 L1 and HPV:HIV VLPs) are different in their actions. We selected 95% confidence intervals alongside the best-fit line. Prism was automatically overlaid a linear regression line on both our data sets and it has plotted a dotted line representing 95% confidence intervals. During the linear regression analysis, the software calculated only the mean Y value of our data set that indicated show the goodness of fit. In addition, Prism gave us a commentary, so we can conclude that the differences between two slopes are extremely significant.n = 4 and female n = 4) in each group. We used Gardasil-9-immunized mice as positive control group and PBS-immunized mice as negative control group. The data of our designed experiments were not matching or pairing. We undertook one-way analysis of variance (ANOVA) to see whether these means were different. We first checked our data fit Gaussian normal distribution. We found that some groups of data in ELISA assay did not past the Gaussian normal distribution test. Therefore, we carried out a non-parametric statistical analysis on these data. By contrast, all groups of data in the ELISPOT assay past the Gaussian normal distribution test. Thus, we preformed a parametric statistical analysis on these data. The significance threshold and confidence level were set to 0.05 . p value showing in general the probability that there are differences between groups. Since our main concern for this experiment is what are the differences between our groups, the multiple comparisons in Prism gave us the outcome of comparison in all groups with every other group.We had 5 sets (ELISA) and 4 sets (ELISPOT) of data collected from mouse immunization experiments. These data sets had an equal number  and approved by local authorities  and Universitat Autònoma de Barcelona Ethics Commitee. The animal experiments strictly conformed to the animal welfare legislation of the Generalitat de Catalunya. All the experiments were approved by the local Research Ethics Committee .The P18I10 peptide from HIV-1 Env third variable domain (V3) loop and T20 peptide from HIV-1 Env membrane‘s proximal external region (MPER) were inserted into to HPV16 L1 DE loop protein to generate chimeric L1:P18I10 and L1:T20 immunogens. The chimeric L1:P18I10 and L1:T20 DNA coding sequence were cloned into pcDNA3.1 (+) plasmid DNA expression vector for transient transfection in 293F cells A. The moSince HPV16 L1 protein C terminal sequence mediates cellular nuclear import machinery during infection , nuclearThe chimeric L1:P18I10 and L1:T20 proteins were produced by using 293F expression system. The capture, intermediate purification, polishing (CiPP) strategy to develop our chromatographic purification protocol is shown in In order to confirm that purified HPV:HIV VLPs displayed similar in vitro stability to HPV16 L1 VLPs, we performed non-reducing SDS-PAGE to evaluate disulfide cross-linking of HPV:HIV capsid proteins A. It is To demonstrate that purified HPV:HIV proteins by chromatography are able to self-assemble to icosahedral particles, we further performed molecular mass analysis under the same reducing condition (5% 2-ME). The commercial HPV16 L1, purified L1:P18I10 and L1T20 proteins without reducing agent treatment were filtered out through 1000 kDa molecular weight cut-off (MWCO) diafiltration devices individually (Transmission electron microscopy (TEM) was used to examine morphologic conformation of HPV16 L1 and HPV:HIV VLPs. The HIV-1 P18I10 and T20 peptides were inserted into DE loops of HPV16 L1 protein, respectively. These commercial HPV16 L1 and chimeric HPV:HIV capsid proteins can spontaneously self-assemble in vitro into integral VLPs in a diameter of approximately 50–60 nm , designated CAMVIR-1, to recognize the highly conserved epitope  of HPV16 L1 protein ,58. A prp < 0.01%). The 2F5 epitope-binding specificity of L1:T20 VLPs was significantly different from HPV16 L1 VLPs (p < 0.01%). These pattern revealed that hydrophobic cellular lipids were not necessary for the binding of 2F5 neutralizing antibodies to HPV:HIV VLPs in vitro. Although the reactivity of anti-HIV-1 gp120 V3 and 2F5 neutralizing antibodies to HPV:HIV VLPs is relatively mild, the binding of anti-HIV-1 gp120 V3 and 2F5 mAb to HPV:HIV VLPs were significantly epitope-specific.Moreover, to determine whether HIV-1 conformational epitopes presented on HPV:HIV VLPs could be identified by the gp120 V3 and 2F5 neutralizing antibodies in vitro, we performed indirect ELISA assay to check the epitope-binding specificity and reactivity. As shown in n = 4) and female (n = 4) mice were evaluated. In the group of L1:P18I10 VLP, L1:T20 VLP and Gardasil-9, anti-HPV16 L1 antibody responses of female mice were on average higher than male mice (p = 0.0041)  B. A veryp = 0.0039). The anti-L1 responses among Gardasil-9, L1:P18I10 and L1:T20 VLP-immunized mice were similar and did not differ significantly (2auxo.int prime and L1:P18I10 VLP boost mice elicited a very low level of anti-L1 IgG. These results suggested that HPV:HIV VLP-immunized mice produced the same level of anti-L1 IgG as Gardasil-9-immunized mice (p = 0.005) (data not shown). In L1:T20 VLP group, a significantly higher antibody response against T20 peptide was detected compared to Gardasil-9 group (p = 0.0083). As expected, anti-T20 titers were undetectable in Gardasil-9, PBS, L1:P18I10 VLP and rBCG.HIVA prime combined with L1:P18I10 VLP boost groups  of HPV16 L1 VLPs used as stimuli. The group of BCG.HIVA2auxo.int prime and L1:P18I10 VLP boost induced higher frequency of IFN-γ secreting splenocytes and significant difference in IFN-γ secretion were observed when compared with mice vaccinated with Gardasil-9 group (p = 0.0103). 3 out of 8 mice (~38%) elicited the highest L1-specific IFN-γ responses (6 splenocytes was observed in BCG.HIVA2auxo.int primed mice compared to mice receiving Gardasil-9 vaccines or L1:P18I10 VLPs. Mice primed with BCG.HIVA and boosted with L1:P18I10 VLPs elicited significantly higher IFN-γ secretion compared with mice vaccinated with L1:P18I10 VLP homologous prime-boost (p = 0.0268). In addition, a significantly higher IFN-γ secretion was observed in mice vaccinated with L1:P18I10 VLPs in comparison with mice receiving Gardasil-9 vaccines (p = 0.0157)  C. As expBoth HPV16 and HIV-1 are sexually transmitted diseases and are currently the focus of many vaccine studies. Although HPV prophylactic vaccines have been commercialized and HIV-1 transmission has been greatly controlled by anti-retroviral treatment (ART) and PrEP, an effective, safe and affordable chimeric HPV:HIV vaccine against both viruses is an urgent need. In this study, (1) we demonstrated that the 293F expression system and the chromatographic purification method could be feasible approaches to produce and purify chimeric L1:P18I10 and L1:T20 VLPs; (2) we confirmed that the insertion of P18I10 or T20 peptides into the DE loop of HPV16 L1 capsid proteins did not affect in vitro stability, self-assembly and morphology of chimeric HPV:HIV VLPs; (3) The sequential and conformational P18I10 or T20 peptides exposed to DE loops of chimeric HPV:HIV VLPs could be detected by anti-HIV-1 gp120 V3 and 2F5 neutralizing antibodies in vitro; (4) The chimeric L1:P18I10 and L1:T20 VLPs could elicit HPV but weak HIV-1-specific binding antibodies in BALB/c mice. Furthermore, the insertion of HIV-1 P18I10 or T20 peptides into HPV16 L1 protein did not affect HPV16 L1-specific antibody induction in vivo; (5) L1:P18I10 VLPs could induce both HPV16 and HIV-1-specific T-cell responses; (6) BCG.HIVA prime and L1:P18I10 VLP boost elicited highest magnitude of IFN-γ producing splenocytes in comparison with L1:P18I10 VLPs homologous prime-boost in BALB/c mice. These finding supported further development of HIV-1 vaccines based on rBCG and chimeric HPV:HIV VLPs. All in all, this study provides a baseline strategy that may be worthy to support the global efforts to develop novel chimeric VLP-based vaccines for controlling HPV and HIV infections.In this study, L1:P18I10 and L1:T20 VLPs could induce the same level of anti-HPV16 L1 binding antibodies as HPV Gardasil-9 vaccine. However, L1:P18I10 and L1:T20 VLPs only elicit low level of P18I10 and T20 epitope-specific HIV binding antibody responses. We hypothesized that might be due because ELISA assay plates were coated with recombinant HPV16 L1 protein, HIV-1 P18I10 peptide and HIV-1 T20 peptide, respectively. The murine anti-L1 antibodies induced by our L1:P18I10 and L1:T20 VLPs might target multiple binding epitopes of L1 protein. By contrast, murine anti-HIV-1 antibodies elicited by our L1:P18I10 and L1:T20 VLPs only target single HIV peptide (P18I10 or T20) on HPV:HIV VLPs. Consequently, the overall maximum OD450 values of anti-HIV-1 binding antibodies were much lower than anti-HPV16 L1 antibodies.The reason that we selected HPV16 L1 capsid protein DE loop as preliminary insertion region of HIV-1 immunogen referred to a previous study that immunized mice with bovine papillomavirus (BPV):HIV VLPs for inducing antibody responses . It is kThe length and site of optimal HIV-1 foreign antigen incorporated into the HPV16 L1 VLPs and the in vitro stability of the resulting chimeric HPV:HIV VLPs should be verified before mice immunization. Our current study have shown that the insertion of P18I10 or T20 peptides into HPV16 L1 protein did not affect in vitro stability, self-assembly and morphology of chimeric HPV:HIV VLPs. These results were in concordance with previous studies indicating that insertion of HIV-1 MPER domain into BPV L1 DE loop sequence did not influence the capacity of BPV L1 capsid protein self-assemble to VLPs . Here, wSelf-assembly is a representative index of in vitro stability of HPV16 L1 VLPs. It is known that pH, ionic strength, temperature  and redoThe P18I10 peptides derived from HIV-1 gp120 V3 loop are presented in HIV-infected cells by major histocompatibility complex (MHC-I) class I molecules . CD8+, cBroader CD8+ T-cell responses against multiple conserved CTL epitopes are beneficial to overcome HIV-1 genetic diversity and escape ,99,100. Currently, our research group is focusing on the development of promising rBCG:HIV vaccines expressing novel HIV-1 T-cell immunogens, such as tHIVconsvX and HIVACAT (HTI) T cell immunogen, to improve HIV-1 variant match and T-cell response breadth. The 2nd-generation HIVconsvX immunogens were designed by redefining the group M conserved regions and utilizes a bivalent mosaic design to maximize the match of potential 9-mer T-cell epitopes in the vaccine to global variants . The HTIThe T20 peptide contains a highly conserved linear epitope 2F5 (ELDKWA). The 2F5 antibody collected from long-term HIV-infected patients was reported to have broadly neutralizing efficacy ,107. The


The advent of graphene opens up the research into two-dimensional (2D) materials, which are considered revolutionary materials. Due to its unique geometric structure, graphene exhibits a series of exotic physical and chemical properties. In addition, single-element-based 2D materials (Xenes) have garnered tremendous interest. At present, 16 kinds of Xenes  have been explored, mainly distributed in the third, fourth, fifth, and sixth main groups. The current methods to prepare monolayers or few-layer 2D materials include epitaxy growth, mechanical exfoliation, and liquid phase exfoliation. Although two Xenes  have not been synthesized due to the limitations of synthetic methods and the stability of Xenes, other Xenes have been successfully created via elaborate artificial design and synthesis. Focusing on elemental 2D materials, this review mainly summarizes the recently reported work about tuning the electronic, optical, mechanical, and chemical properties of Xenes via surface modifications, achieved using controllable approaches  to broaden their applications in various fields, including spintronics, electronics, optoelectronics, superconducting, photovoltaics, sensors, catalysis, and biomedicines. These advances in the surface modification of Xenes have laid a theoretical and experimental foundation for the development of 2D materials and their practical applications in diverse fields. Graphene, initially isolated from graphite via mechanical exfoliation, possesses a layered honeycomb structure and exhibits fascinating electrical and thermal properties . SubsequOver the past few years, many studies have focused on searching for other 2D Xenes with distinctive and exciting properties beyond graphene a 18,19],1918,19]Even though 2D Xenes have demonstrated great potential in numerous applications, their intrinsic properties usually constrain the expansion of these applications. For instance, despite the high mobility, the gapless band structure in graphene restricts its applications in electronic devices. Therefore, finetuning the properties of 2D Xenes plays an essential role in overcoming their intrinsic constraints ,35,36,37The material properties  of 2D Xenes are not only determined by their chemical compositions but are also strongly associated with the atom arrangement in the lattice. Due to the preferred orbital hybridization of various elements in the main group, 2D Xenes have been theoretically predicted or experimentally verified to possess allotropes with diverse crystal lattices . The rep1−ν☐ν; ν represents the vacancy concentration) with various vacancy concentrations and 2D aluminene with various forms Galleneneubstrate .Graphene. The sp2 hybridization of carbon atoms leads to the formation of flat honeycomb graphene with a σ bond between neighboring carbon atoms 118] but of 1.7 K f,g 52]..c of 1.7Silicene. Silicene, the silicon analog of graphene, was first predicted in a theoretical study . . 168]. BB-doping . With a B-doping . In addiB-doping . When axB-doping . MoreoveB-doping .Arsenene. Arsenene mainly has two kinds of allotropic structures, including buckled and puckered . T. T4 clusnochains b,c 24]..4 clustenochains d,e 177]4 clusternochains f, indicaf 30.8 K . Indeed,f 30.8 K . Meanwhif 30.8 K . In addif 30.8 K .Antimonene and bismuthene. The most stable structures of antimonene and bismuthene are α-form (puckered) and β-form (buckled), which are the monolayers of black and gray bulk allotropes, respectively. Monolayer β-Sb and β-Bi possess indirect bandgaps of 2.28 and 0.99 eV, respectively, whereas the direct bandgaps of monolayer α-Sb and α-Bi are 1.18 and 0.36 eV, respectively [ectively ,182,183.ectively ,185,186.Doping with 3d transition metal atoms for antimonene can lead to significant changes in the bandgap and the magnetic moment . For Cr-Selenene and tellurene. Selenene has been predicted to have three allotropic structures, including a 1T-MoS2-like structure (t-Se or α-Se), a tiled helical-chain structure (c-Se), and s square structure (s-Se) [2-like, rectangle, and 2H-MoS2-like structures, respectively [e (s-Se) . Both t-e (s-Se) . Howeverectively . It was ectively . Therefoectively ,196. MeaAs mentioned above, 2D Xenes possess various physical and chemical properties, such as flexibility, layer-dependent semiconducting, high carrier mobility, molecule and light sensitivity, topologically nontrivial band structures, etc.c of 30.8 K [2/graphene hybrids decorated by CdS nanocrystals can act as high-performance photocatalysts for H2 evolution under visible light irradiation [In order to utilize 2D Xenes more effectively, surface modifications become particularly important  to tune f 30.8 K . Iodine-f 30.8 K . Graphenf 30.8 K . MoS2/gradiation . Moreoveadiation . For exaadiation . Polyethadiation . OverallIn total, except graphene, 15 different elemental 2D materials of the main group elements have been experimentally created or theoretically predicted to date. In fact, 14 Xenes, including borophene, graphene, silicene, phosphorene, gallenene, germanene, arsenene, selenene, stanene, antimonene, tellurene, thallene, plumbene, and bismuthene, have been successfully grown on proper substrates using epitaxial methods. Although a lot of research, engineering, and development related to 2D Xenes—most of which were investigated theoretically—has been reported in recent years, experimental studies are still desperately required for the development of synthesis strategies and novel applications. Before realizing the surface modifications of 2D Xenes for the applications of interest, three significant challenges need to be overcome:(i) The synthesis strategies of 2D Xenes must not only ensure reliably large-scale production but also be tailored for the requirements of the application. For example, the applications of electronics and batteries demand low costs and scalable techniques, while plasmonics and spintronics require high fidelity and reproducible techniques. Hence, reliable synthesis approaches play a crucial role in functional design and practical applications.(ii) The strategies to enhance the environmental stability and mitigate the degradation of 2D Xenes must be taken into consideration for certain applications. For instance, an optoelectronic device based on black phosphorene must be concerned with ambient stability, requiring appropriate encapsulation or the passivation of the surface.(iii) Many of the predicted and fascinating properties of 2D Xenes require further efforts to find strategies for their implementation, which may offer opportunities to discover revolutionary technologies. In addition, the exciting and novel properties necessitate not just “one-off” research, but also statistical evaluation to ascertain their viability and accessibility on a commercial scale.Despite the challenges ahead, the exceptional properties of 2D Xenes will significantly impact future applications in various fields. It is hoped that this review will inspire more exhilarating discoveries and applications in the growing family of 2D Xenes.


Azadirachta indica (Neem) extract with an objective to develop new coating materials. The nanomembranes have been synthesized by electrospinning machine over aluminum foil paper using the raw materials PVA grain, SiC, TiO2, Graphene, and neem. The nanomembranes have been characterized by SEM, XRD, FTIR, Surface Roughness, antibacterial, and Cytotoxicity test. FTIR analysis established the presence of PVA and neem indicating the formation of different organic compounds. It also confirmed that no chemical reaction occurred during the synthesis process. The membrane's roughness analysis obtained average roughness values from 1.15 to 3.84. The formation of homogeneous and smooth membranes with the formation of micropores was confirmed by SEM analysis. Miller Indices identified different types of crystal structures in XRD analysis. Antibacterial activity increased with the increase of the percentage of neem confirmed by the antibacterial test. No toxic effects were observed from the membrane during the cytotoxicity test. The obtained data confirmed that the synthesized nanomembrane could be used in different biomedical applications.This paper presents the coating technology on Nano membrane using SiC–TiO2-Graphene with varying percentages of  •Azadirachta indica.Synthesis of Nano membrane using SiC–TiO2-GRAPHENE with varying percentages of •Synthesis by electrospinning machine.•Increased antibacterial activity.•Characterized by SEM, XRD, FTIR, Surface Roughness, Antibacterial and Cytotoxicity test. Nano membrane; Neem; PVA; Antimicrobial activity; Cytotoxicity. Nanotechnology is used widely in a different range of applications, particularly in the field of energy, biotechnology, sensors, and related other areas. Nanotechnology has brought immense creativity and has pushed the limits of our understanding. The most recent technological advances will allow a much wider and more in-depth analysis of Nanoscale materials structures and functions. Nanotechnology and Material Science require integrating and comprehending the physical ideas shown by Biomaterials, nanometer-scale particle technology, and other nanotechnologies. Materials as well as innovative applications combining different areas of nanotechnology are invited. Scientists as well as engineers are brought together from different disciplines such as materials science, forensic engineering, biomedical engineering, chemical engineering, electrical engineering, physics, microtechnology, nanorobots and nanosensors , 2, 3. DNanomembrane can be defined as an organic, inorganic, or quasi-2D artificial freestanding or free-floating structure having a thickness less than 100 nm . In the The electrospun nanomembranes are being developed by incorporating different bioactive nanoparticles to improve tissue regeneration ability. Different nanoparticles such as bioactive glass nanoparticles , graphenTitanium dioxide nanoparticles have a wide range of applications such as reducing toxicity in dyes and prescription drugs; wastewater treatments; silkworm reproduction; space applications; food industry; etc. For industries, the atmosphere, and agriculture, the applications of nanoparticles synthesized with a biological approach would be favorable . In ordeThe tribological behavior of graphite nanoparticles were evaluated using vegetable based oil as lubricant with the help of a pin on disc tribometer. Investigation was performed on graphite nanopartilces grease instrument. The results indicated that the vegetable based oil reduced the friction and wear significantly .Azadirachta indica (Neem) extracts. In our real life, people suffer several kinds of bone diseases in which bone fracture very vital problem. So, in medical science, they try to reduce bone fracture by using metal. But metal is not safe for such a kind of operation. Metals contain toxic features and have bacterial effects. Therefore, this experiment will reduce those kinds of harmful effects of metals.In this study, an attempt has been made to reduce the toxicity and bacterial effect of the multi-nanoparticle's membranes for biomedical applications by infusing nanoparticles with the nanomembrane. The toxic and bacterial impacts of SiC–TiO2- Graphite membranes are purified by 5%, 10%, and 15% of 2-Graphene hybrid nanoparticles in PVA solution to increase the versatile multifunctional aspect of this bio-based nanomembrane to be applied as a biomaterial in different biomedical applications which cannot be obtained when a single nanoparticle is used. In nanofibrous membrane, a large surface area to volume ratio, flexibility in surface functions, and increased stiffness and tensile strength when compared to other materials since fiber diameters are lowered from micro to nanoscale. There is large surface porosity with small pore size in nanomembrane when the nanoparticles are absent there. This type of porous nanomembrane is suitable for water filtration, high energy generation, and some other areas. But when nanoparticles are considered as nanofillers coatings in PVA nanomembrane, the porosities are disclosed and reduced to enhance the stiffness, strength, wear resistance, fatigue resistance, reduction of thermal expansion, and dimensional stability. These nanoparticles also have their inherent properties; these have also a considerable effect on nanomembrane properties. The concept of this type of nanofibrous-nanofiller membrane can be used in dental implants to mitigate the complication of stress shielding and implant-related infections and inadequate osseointegration problem.The novelty of this study is to use SiC–TiOBesides this, GTR (guided tissue regeneration) and GBR (guided bone regeneration) are surgical methods used to regenerate the tooth-supporting tissues (GTR) and the alveolar bone (GBR) in edentulous areas, respectively (GBR). Recent techniques include the use of resorbable membranes/nanofiller. These materials have the advantage of disintegrating over time, eliminating the need for surgery to remove the scaffolds. Nanofibrous scaffolds have improved mechanical qualities, cell adhesion, biocompatibility, and antibacterial properties for GTR/GBR applications. This study can be used as a guideline for future research to resolve the problem using this type of nanofibrous-nanofiller membrane but before using this concept biodegradability should be ensured. Therefore, the choice of nanofiller in the nanofibrous membrane is important. The concept of the nanofibrous-nanofiller electrospun membrane in GTR/GBR dental application is illustrated in Titanium and its alloys are recognized one of the best biomaterials for dental implant applications for their excellent properties such as higher tensile strength, higher corrosion resistance, and effects resistance due to body fluid, flexible and ferromagnetic abilities. Unique mix strength, biocompatibility, and low reactivity made them suitable for biomedical applications , as wellTo ensure ion releasing, ion element identification, survival rate, non-toxicity, and cell growth confirmation, corrosion tests in artificial body fluids such as SBF, HBSS, in vitro test, cell viability test of degraded corroded solution using fluorescence microscopy, microwave plasma atomic emission spectroscopy, and cell attachment test using the chemical process are conducted. These tests are not observed in this study as there are many results available in the literature , 29, 30.22.12 nanopowder, and Graphene nanopowder. PVA is collected from sigma, having a molecular weight of 98,000g (99% hydrolyzed). SiCnano powder, TiO2 nanopowder, and Gr nanopowder are purchased from Shanghai Ruizheng Chemical Technology Co., Ltd of China. Their chemical and physical properties are available in the literature [The materials used in this experiment are PVA, SiC nanopowder, TiOterature , 33. Nee2.2Neem leaves were collected from the Dhaka University of Engineering and Technology garden during the winter season. The tree was around three meters tall. The collected leaves are washed three times with distilled water to remove the dirt and other impurities and then dried under the sun. Then the leaves are cut into small pieces. 20 gm of leaves are taken and kept in a glass jar with 200 ml ethanol and kept at 4 °C for 24 h. The next day, the solution turned to greenish color. The solution is then filtrated to remove any solid particles and kept in the refrigerator for further use .Figure 22.315 gm of PVA is put in a beaker and mixed with 300 ml distilled water at 70 °C temperature over a magnetic stirrer to form a uniform solution.2.42, and 0.2 gm Graphene nanoparticles are mixed together at room temperature by continuous stirring to obtain a combined mixture and the mixture was then dissolved with 20 ml PVA solution under a magnetic stirrer and kept in three different jars. The solution was stewed overnight at room temperature to remove bubbles. Then 0%, 5%, 10%, and 15% neem were added to the mixture in the jar. Later, the solution was injected into a syringe with having 0.9 mm inner diameter with a metal nozzle shown in 0.2 gm SiC, 0.2 gm TiOIn the electro-spun process, the syringe is filled with the requisite solution. The syringe is inserted into the pump and joined by a pipe to some needles. The outside of the drum collector is wrapped in aluminum foil. The positive and negative voltage terminals are linked to the needles and the collector, respectively. In relation to SiC–TiO2-Gr and NEEM extraction on the surfaces of aluminum foil, a magnetic field is produced between needles and the collector as a result of positive and negative voltage potentials, which electrifies the liquid droplet of the solution to produce a jet. The jet is then stretched and extended to produce a nanofiber network.The electrospinning had a 15 cm distance between the fiber collector and spinneret, 25 kV power supply, 0.5 mL/h spinning solution feed rate, and 25 °C temperature. Later, the membrane was dried at room temperature. 2.52.5.1−1 to 4000 cm−1.FTIR analysis has been performed by FTIR spectrometer made by PerkinElmer, the USA maintaining the frequency range from 500 cm2.5.2The surface roughness of the synthesized nanomembrane was estimated by a surface harshness analyzer . Three areas of the surface were estimated at any rate and the average value was considered.2.5.3The microstructure of the surface of the synthesized nanomembranes was examined by a scanning electron microscope made by Hitachi, Japan having model number SU1510.2.5.4The SEM images were analyzed then by SPIP software for better realization of the microstructure of the surface by 2D and 3D images.2.5.5The SEM images were further analyzed by SPIP software as well to analyze the particle distribution on the surfaces of the synthesized nanomembrane.2.5.6−1.The synthesized nanomembranes were analyzed by Bruker D8 advanced X-ray beam diffraction analyzer which was made in Germany. The X-ray beam force was estimated in the scope of 100 ≤ 2θ ≤ 600 with a sweep speed of 0.50 min2.5.7Staphylococcus aureus (ATTC 25923) as gram-positive bacteria were subjected to the tests in the disc having a size of 6 mm × 6 mm. The bacterial cell concentration was 1000 CFU/ml and the nanomembrane sample concentration was 200 mg/ml. The bacterial cells used in this research were collected from Dhaka University. The culture was spread on a nutrient agar plane after suspending in nutrient broth. The culture was incubated at 37 °C for 24 h. The culture was picked off from the agar plate with an inoculating loop and two single colonies were suspended in a nutrient broth that had a 10 mL volume. Later, the culture was incubated for 18 h at 100 rpm and 37 °C. 0.3 mM M and pH 7.2 sterile buffer solution were used to dilute and a final concentration of 1000 CFU/ml was obtained.The antibacterial test of the nanomembranes was accomplished by applying the Kirby-Bauer disk diffusion test method maintaining the ASTM E2149-01 standard. The bacterial cell 2.5.8The cytotoxicity tests of the nanomembrane were performed in a biological biosafety cabinet model NU400E, incubator, Trinocular microscope with camera, and Hemocytometer. All the equipment is made by Nuaire, USA. Vero cell line, a kidney epithelial cells extracted from an African green monkey, was maintained in DMEM (Dulbecco's Modified Eagles' medium) containing 1% penicillin-streptomycin (1:1) and 0.2% gentamycin and 10% fetal bovine serum (FBS). Cells (1.5 × 104/100 ul) were seeded onto a 48-well plate and incubated at 37 °C + 5 % CO2. The next day, a sample (Autoclaved) was added to each well. Cytotoxicity was examined under an inverted light microscope after 48h of incubation. Duplicate wells were used for each sample. Vero cell line, a kidney epithelial cells were supplied by the WAFFEN Laboratory, Dhaka, Bangladesh.33.1−1 because of less oxidation effect due to the absence of neem. Alkyl amine stretching vibration is shifted to 1090 cm−1 in the nanomembrane containing 5% neem extract due to oxidation. Further shifting of alkyl amine stretching vibration is observed attributed to 1088 cm−1. Medium stretching functional group O–H is attributed to 3320 cm−1 [−1 [−1 [320 cm−1 . Besidescm−1 [−1 . Medium  [−1 [−1 . The pre3.2Figures 3.3Figures 3.43.52, Graphene, and neem present on the surface of the nanofibrous membrane shown in SEM images of 2 decreased with 5% addition of neem but increased with the addition of 10% and 15% of neem. It is also an indication that the addition of neem increased the density of nanomembrane. However, the mean value increased with 5% addition of neem but decreased with 10% and 15% neem addition.Partilce analysis observed the presence of PVA, SiC, TiO3.6XRD analysis was performed to determine the crystallinity of the developed nanomembrane films shown in 3.7Staphylococcus aureus makes it resistant and the polycationic group present in the nanomembrane facilitates the disruption of gram-negative bacteria [Staphylococcus aureus virus indicating their combined effect. The leaching of antibacterial bioactive constituents from the nanomembrane may cause the incorporation of the neem extract. Besides, bacteria cannot penetrate the mesh structure of the developed nanomembrane due to the presence of micropores and thus the surrounding infections are nullified effectively [Staphylococcus aureus. The presence of tetratriterpenoids including azadirachtin in neem made this possible. The inhibition of the Staphylococcus aureus production polysaccharide intercellular adhesion is possible by these compounds due to the inhibition of the ica genes expression [The antibacterial activity of the synthesized nanomembrane can be seen in bacteria , 53. Howectively , 55. Thepression , 57.Figu3.8The cytotoxicity of the developed nanomembrane was observed on the Vero cell line and the results confirmed the survival of all cell lines. There are no significant changes in the cell line. The study revealed that the developed nanomembrane can safely be used against infections. Ion complexity by legends may be the reason for the zero or near zero toxicity of the developed nanomembrane.4Staphylococcus aureus with zero or near zero toxic effect. The morphological analysis confirmed the formation of smooth nanofiber with the development of micropores. FTIR spectra demonstrated the characteristic peaks and the peaks became sharper with the increased percentages of neem. Micropores present in the nanomembrane will inhibit the bacteria and keep the skin safe. The addition of neem increased the fiber diameter. Regardless of the percentage of neem, all the developed nanomembranes formed crystal structures confirmed by the XRD analysis. Besides, variation of surface roughness with the various constituent percentages of neem is confirmed by surface roughness analysis. The formation of inhibition zones by the developed nanomembranes was higher than amoxicillin. The overall findings of the present study suggest that the developed nanomembrane can successfully be sued as bio-based antibacterial wound dressing material. This nanofiller-nanofibrous membrane concept can be applied in dental applications with enhanced bacterial, structural, particle distribution, surface, and chemical bonding properties.A new way of developing nanomembrane with the help of electro-spinning techniques has been introduced in this work with antibacterial resistance against Dr. Mohammad Asaduzzaman Chowdhury: Conceived and designed the experiments.Mr. Nayem Hossain: Performed the experiments; Wrote the paper.Dr. Md. Abdus Shahid, Md. Jonaidul Alam: Analyzed and interpreted the data.Sheikh Monir Hossain, Md. Ilias Uddin, Md. Masud Rana: Contributed reagents, materials, analysis tools or data.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.Data will be made available on request.The authors declare no conflict of interest.No additional information is available for this paper.


A novel and facile pretreatment method is introduced based on ultrasonic treatment with nickel nano-particles as the catalytic core. This method abandons the sensitization and activation process in the traditional pretreatment that reduces the time and economic cost dramatically. The static contact angle was determined by an Olympus BX51M optical microscope. The surface morphology and plating composition were characterized via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS), the infrared radiation (IR) transmittance spectra of the copper plated graphene were measured by Fourier transform infrared spectroscopy (FTIR), the layer structure was measured by Raman spectrum, the phase identification was identified by X-ray diffraction (XRD), the thermogravimetric analysis (TGA)  was carried out to detect the thermal characteristics. The electrical resistivity of copper-plated graphene was performed in an especially designed apparatus. The results show that the surface of graphene is coarsened, and the size is reduced after ultrasonic treatment, which can facilitate the nucleation and fine particle distribution of metal. The electroless plated efficiency of copper of the nickel pretreatment copper-plated graphene is 64.27 wt%, higher than that of generic copper-plated graphene at 58.62 wt%. The resistivity decreases rapidly from 1.69 × 10 The attractive properties of graphene have made them desirable templates for “core–shell” 2D metal/graphene nanocomposites , with graphene as the matrix and metal as the outer shell4. This metallization process belongs to a sort of surface modification of graphene, not only add the surface active sites to improve the bonding strength between graphene and other materials  but can maintain the superior intrinsic properties of graphene in the composites5. This metallization of graphene has been demonstrated to have significant potential for the fabrication of noble powdered metal/graphene composites, thus extending the application fields of graphene in corrosive resistance coating6, electrical contact materials7, electromagnetic interference8, active catalyst9.Since the discovery of graphene in 2004, a window to new technological fields has been unbarred. Due to its perfect two-dimensional (2D) lattice structure of sp28/m3). Due to its low cost, high solder ability, electro-migration resistance, and high electrical conductivity and thermal conductivity, copper has attracted the special attention of researchers for a wide range of applications. Due to its special structural properties and hydrophobic nature, the common methods such as low-temperature powder metallurgy, and chemical vapor deposition are insufficiently strong to guarantee significant adhesion between copper and graphene. Also, the tendency of agglomeration through strong Van der Waals interaction reduces the active site of graphene and curbs the formation of a copper layer with a homogenous distribution. Electroless plating is a kind of process which is widely used in modifying the surface of various materials like non-conductors, semiconductors, and metals, during which the metal ions in the solution are reduced into metal nanoparticles under a strong and appropriate reducing agent without external electrical assistance, and deposited on the surface with catalytic active sites of the matrix for forming a compact metal plating layer10. In particular, electroless plating is of great significance for improving the conductivity and service life span of some materials with high abrasive resistance requirements, such as electric contact materials. In addition, the core–shell structure composites prepared by electroless plating have good anti-fretting corrosion and anti-wear resistance properties11. Due to lack of catalytic sites, inert graphene does not possess autocatalytic activity, which generally needs to be pretreated by sensitization and an activation process during electroless plating, some complex technical problems still exist in these two-step processes12. For instance, if the activation solution contains noble metal salts , the cost of noble metal would limit the wide applications of noble metal activation13. Stannous chloride (SnCl2) is frequently used in the sensitization process, and it can be hydrolyzed to form hydrogel and adhere to the surface of material easily14. However, the residual tin ions on the surface have an adverse impact on the uniformity and adhesion of the copper plating, resulting in an undergrade quality of electroless plating15. Most studies used strong acids, strong bases, strong oxides, or high temperatures to obtain new and rough surfaces, which are not environmentally safe17.Metal Cu has the second lowest resistivity in the natural environment and has a large free electron density  solution and supersonic wave for the pretreatment of the surface of graphene to produce metal catalytic cores and surface defects as the active site for the direct electroless copper plating. Compared to the conventional process, this approach is simplified effectively. It does not refer to any noble or poisonous metals or an expensive instrument that will dramatically reduce the process cost and cause less environmental pollution. The surface morphologies, phase composition, and electrical properties of resulting Cu/Ni@Gr composites were characterized.In this paper, a simple and economical pretreatment without two-step sensitization and activation is carried out on graphene. It utilizes a nickel sulfate hexahydrate  chloride (PdCl2), copper (II) sulfate pentahydrate (CuSO4·5H2O), EDTA Disodium Salt 2-hydrate (EDTA 2Na), potassium Sodium Tartrate (NaKC4H4O6·4H2O), formaldehyde, Potassium hexacyanoferrate(II) trihydrate (K4[Fe(CN)6]·3H2O), NiSO4·6H2O, sodium borohydride (NaBH4) were all from ALCHIMICA s.r.o. and of analytical grade without further purification. Hydrochloric acid (37%), nitric acid (70%), sodium hydroxide, and ethanol were provided by Sigma-Aldrich.The average sizes of graphene used in this research are 18–25 μm, purchased from supplier Epinikon a.s. as the main ingredient in this research. SnCl4·6H2O (20 g/L) was dissolved in deionized water with mechanical agitation. After degreasing, the graphene was added at room temperature with probe-type ultrasonic processing for 12 min and then transferred to mechanically stirring for 30 min. During this procedure, the surface coarseness of graphene and the adsorption of nickel ions can be accomplished simultaneously and efficiently. After filtration, the graphene deposited with nickel ions was added into a NaBH4 solution (0.5 mol/L) with mechanically stirring to reduce the Ni2+ to Ni0  and HCl (60 mL/L) mixed solution by mechanically stirring for 15 min. After that, the sensitized graphene was blended with the solution of PdCl2 (0.25 g/L) and HCl (10 mL/L) by agitating for 15 min to actualize activation 6]·3H2O and NaOH, the NaBH4 as reducing agent. The detailed composition of the electroless copper plating bath is listed in Table The activated graphene was taken into an electroless copper plating bath in 100 mL quantity. The plating bath containing CuSO25:The synthesized graphene composites were characterized by UHR-SEM Zeiss Ultra Plus with an accelerating voltage of 2 kV equipped with an Energy Dispersive X-ray (EDX) spectrometer Oxford X-max 20. EDX analysis of the resulting composites was performed at 10 kV accelerating voltage to confirm the elemental configuration of the deposited materials on the surface of graphene, all the samples were gold-sputtered and carefully handled to avoid contaminations. Malvern zetasizer nanoparticle characterization system was used to study the particle size distribution. The static contact angle was determined to describe the hydrophilicity improvement of graphene after ultrasonication treatment by an Olympus BX51M optical microscope fitted with an Olympus E-510 digital single-lens reflex camera. The electroless plated efficiency of copper  with a 532 nm laser and full range grating with 900 lines/mm was used. Samples were placed under the lens of an Olympus optical microscope at 10 × magnification. The spectra were obtained in the range of 3500–50 cm−1. X-ray diffraction (XRD) was carried out using X׳Pert PRO MPD diffractometer  in Bragg–Brentano geometry equipped with a Co X-ray tube (iron filtered CoKα radiation: λ = 0.178901 nm), all materials were prepared on zero-background Si slide and measured in 2θ range 5°–105° (resolution 0.017° 2θ).The Fourier transform infrared spectroscopy (FTIR) spectra of the copper-plated graphene were measured by Nicolet iZ10 Thermo Scientific infrared spectrophotometer (KBr pellets) in the range of 4000–400 cmThermogravimetric analysis (TGA)  was carried out to detect the thermal characteristics of copper plated graphene in the temperature range of 25–800 °C at a heating rate of 10 °C/min. The measurements were performed under a nitrogen atmosphere at a flow rate of 25 mL/min. The ohmic heating behavior of samples was estimated using an electrical power supply (TIPA SP3010) with a clamping distance of 0.5 cm, and an infrared camera  was used to monitor the temperature change on the sample surface. Before testing, the particles were compressed into a circular sheet with a diameter of 1 cm by a mold.26:The electrical resistivity of copper-plated graphene was performed in an especially designed apparatus, which is schematically shown in Fig. Manuscripts reporting studies that do not involve human/animal participants, human/animal data, or human/animal tissue.The ultrasound cavitation in low frequency can etch the surface of the metal and make it rough. Figure a) and after (b) nickel pretreatment under ultrasonic sound. The raw graphene particles have a stacked layered structure that the surface is comparatively smooth. While the nickel pretreated graphene shows a crimping and rough surface, the particles changed into angular ones. Therefore, the specific surface of graphene increased. And the average particle size also reduced from 19.620 ± 0.395 μm of the raw graphene to 14.287 ± 0.326 μm after pretreatment, indicating that the nickel pretreatment not only gave it more metal catalytic cores but also reduced the size of graphene. As shown in Fig. 27. But for graphene, very few functional groups take part in chemical reactions during the electroless plating process. Metal ions are inclined to aggregate and nucleate at the defects and activated sites where nucleation energy is low on the surface of graphene28. The typical cauliflower structure of copper deposition is observed at the edge of graphene with higher magnification  characteristic reflection peak of nickel, located at 2θ = 44.5° is observed in the Ni@Gr, whereas it disappeared in the Cu/Ni@Gr. This might be due to the copper layer deposited on the surface of Ni@Gr, where the nickel had functioned as nucleate points. And the peak observed at 2θ = 63.4°(440) could be attributed to face-centered cubic Fe3O4, which came from residual K4[Fe(CN)6]·3H2O during copper plating process.Figure 30. Figure −1, 1581.66 cm−1, and 2680.28 cm−1 are displayed in original graphene and nickel functionalized graphene, which corresponds to D, G, and 2D peaks, respectively. The G peak (1580–1590 cm−1) is the main characteristic peak of graphene, mainly formed by the in-plane vibration of carbon atoms, which is very sensitive to the number of graphene layers. As the number of layers increases, the G peak moves toward the direction of the lower position, indicating the weakening of bond energy between graphene layers. An empirical formula for calculating the number of graphene layers31:−1) is generally considered to be the disordered vibration peak of graphene, which is caused by the lattice movement away from the center of the Brillouin region and is used to characterize defects in the graphene specimen. The 2D peak (2680–2700 cm−1) is a biphonon resonant Raman peak, which can also be used to evaluate the number of graphene sheets. It is known that the electronic dispersion of multilayer and monolayer graphene is different, leading to the obvious difference in Raman spectra32. From Fig. 2D/IG of Gr and Gr/Ni are about 0.24 and 0.29, respectively, compared with that of the single-layer graphene is around 2 and bi-layer graphene is around 1. However, after electroless copper plating onto the surface of the particles, the characteristic peak of grapheme disappeared, indicating that the graphene had been deposited with copper nanoparticles.Raman spectroscopy is an ideal tool to analyze the quality, thickness, and uniformity of graphene and its derivatives in detail34. It coincides with two wide peaks of the DTA curve in Fig. 4 to NiO and SO3. As for Fig. 35. Figure Thermal stability measurement is a versatile approach to characterize the property of the plating layer, it describes the thermal resistance of the compounds by heating them. Thermal stability can be analyzed by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Figure 36:28/m3), after electroless copper plating on graphene by ultrasonic-assistant, the resistivity of the samples has been greatly improved.Figure –2 Ω cm of the original Gr to 0.79 × 10–2 Ω cm of Cu/Ni@Gr and 1.07 × Ω cm of Cu@Gr due to the large number of fine copper particles scattered around the graphene, which can be beneficial to build a high qualified conductive path. Besides, the smaller the size of graphene, the larger the specific surface area and the better the surface adhesion of particles, which is beneficial to the formation of copper crystal nuclei and the growth of crystalline grains. Compared to Cu@Gr, Cu/Ni@Gr has a smaller particle size, leading to a better-plated efficiency of copper on its surface. The above phenomenon is in good agreement with the SEM observations. Novoselov et al.37 found that the electrical resistivity of monolayer graphene is approximately 1 μΩ cm, which is fairly lower than that of the above results. This could be explained as follows, the electrical resistivity of graphene increases with the increasing thickness (a similar behavior can be observed for graphite) due to the inhibited carrier mobility. This is consistent with the results obtained by SEM and Raman analysis that the graphene used in this research has multilayers and contains more defects. And contact resistance between particles must be taken into account in the case of granular materials38.Figure –2 Ω cm of the Gr to 0.79 × 10–2 Ω cm of Cu/Ni@Gr and 1.07 × Ω cm of Cu@Gr, since the large number of fine copper particles scattered around the graphene which can be beneficial to build a high qualified conductive path.The contact angle of ultrasonic treated graphene is 95.5°, much lower than that of pristine graphene 144.7°, demonstrating that graphene made a transition from hydrophobic to hydrophilic properties after the treatment through ultrasonication. The EDS, FTIR, Raman, and XRD spectra show that copper particles were successfully deposited and densely distributed on the surface of graphene. Compared with Cu@Gr, the copper content on the Cu/Ni@G increases from 58.62 to 64.27 wt%. Due to the deposition of the metal layer, the thermal stability of copper-plated graphene has been greatly improved. Thermal IR thermal images of Cu/Ni@G and Cu@Gr display the highest temperature of ∼ 135 °C and ∼ 134 °C, whereas Gr shows the highest temperature of ∼ 112 °C only. The resistivity decreases rapidly from 1.69 × 10


Graphene grown on quartz glass by the CVD method can effectively reduce the wrinkles and pollution caused by traditional transfer methods. The addition of the CF4 plasma-etched process accelerates the growth rate of graphene on quartz glass. The platinum nanoparticles (PtNPs) prepared by in situ sputtering have favorable dispersibility and maximize exposed active catalytic sites on graphene, providing performance advantages in the application of H2O2 detection. The resulting sensor's detection limit , detection linear range (10 nM to 80 μM) and response time (less than 2 s) were significantly superior to other graphene supported PtNPs materials in sensing of H2O2. In addition, the material preparation method was related to the non-transfer CVD method and in situ sputtering technology, allowing for the creation of independent electrodes without additional electrode modification processes. This primitive material preparation and electrode assembly process were promoted for the application and development of practical H2O2 sensors.In this work, chemical vapor deposition (CVD) method-grown graphene on plasma-etched quartz glass supported platinum nanoparticles (PtNPs/eQG) was constructed as an independent transparent electrode for non-enzymatic hydrogen peroxide (H 2O2) detection.In this work, chemical vapor deposition (CVD) method-grown graphene on plasma-etched quartz glass supported platinum nanoparticles (PtNPs/eQG) was constructed as an independent transparent electrode for non-enzymatic hydrogen peroxide (H In recent years, many methods have been developed for the effective detection of H2O2, including the chemiluminescence method,3 spectral method,4 chromatographic method,5 electrochemical method6 and so on. Of these, non-enzymatic electrochemical H2O2 sensors were especially widely used because of their simple equipment, easy miniaturization, high sensitivity, good selectivity and fast response.7–9Hydrogen peroxide  have higher catalytic ability and stability for the detection of H2O2 due to their lower oxidation/reduction overvoltage.20 Therefore, graphene supported PtNPs has attracted great attention for non-enzymatic detection of H2O2 due to favorable properties of graphene as transparent electrodes and ultra-high detection performance of PtNPs.21 For example, Selvakumar Palanisamy22et al. reported a single step electrochemical fabrication of a platinum nanoparticle decorated reduced graphene oxide (RGO–PtNPs) composite for enhanced electrochemical sensing of H2O2. It was linear over the concentration ranging from 0.05 to 750.6 mM with the limit of detection of 16 nM. Their study conclusively reveals the feasibility of the application of graphene nano-platinum composites in electrochemical H2O2 sensing.The sensitivity, selectivity and stability of electrochemical sensors are strongly dependent on the structure and performance of the electrode materials.23 For example, graphene prepared by mechanical exfoliation24 and redox methods25 are agglomerated and have functional group residue, which leads to a decrease in the conductivity and sensing properties of sensors.26,27 At present, graphene grown by chemical vapor deposition (CVD) method has become the most promising material due to their large specific surface area and high crystalline quality.28,29 However, this additional transfer process is extremely prone to resulting in wrinkles, cracks, contamination and defects in graphene. This greatly limits CVD graphene from developing the proper electrochemical properties.30,31Nevertheless, it is still a tremendous challenge to prepare high-quality, large-scale and non-polluting graphene for electrochemical sensing.32 The direct growth of graphene on the target substrate can reduce defects and contamination caused by complex transfer processes and better preserve the physical and chemical properties of graphene. The excellent electrochemical properties of graphene grown on target substrate can improve its potential application in the field of electrochemistry. High-quality graphene produced by non-transfer CVD method can be directly used in self-assembly electrode devices, which is convenient in electrochemistry and promoting the industrialization of CVD graphene.33Direct CVD growth of graphene on the target substrate has immensely aroused research enthusiasm.34 Graphene grown on plasma-etched quartz glass (eQG) combined with sputtered Pt nanoparticles (PtNPs) were used as independent electrodes to assemble electrochemical sensors for non-enzymatic detection of low concentration of H2O2.In this paper, graphene was directly grown on the surface of quartz glass by atmospheric pressure chemical vapor deposition (APCVD). The effect of plasma etching of quartz glass on the growth behavior of graphene was studied.2.2.12) of size of 10 × 5 × 0.5 mm was purchased from Hefei Kejing Crystal Technology CO., LTD . Hydrogen (H2), methane (CH4), carbon tetrafluoride (CF4), nitrogen (N2) and argon (Ar) gases with 99.99% purity were all purchased from Jinan Deyang Special Gas Company . Hydrogen peroxide (H2O2) with a 30% mass fraction, acetone (CH3COCH3), sulfuric acid , sodium dihydrogen phosphate dihydrate (NaH2PO4·2H2O), disodium hydrogen phosphate (Na2HPO4), ascorbic acid (AA), dopamine (DA) and uric acid (UA) were purchased from Sinopharm Chemical Regent Company . Phosphate buffer solution  was a mixture of NaH2PO4 solution (0.1 mol L−1) and Na2HPO4 solution (0.1 mol L−1). All reagents used in the experiments were of analytical grade and used without further purification process. Deionized water with a resistivity of 18.25 MΩ cm was used in all aqueous solutions.Quartz glass (SiO2.2The compact etcher (RIE-1C) was obtained from SAMCO Inc. . The atmospheric pressure chemical vapor deposition (APCVD) equipment was purchased from Xicheng company . Vacuum sputter equipment (DESK V Cold Sputter) was purchased from Denton Vacuum Company . The platinum target with 99.999% purity was obtained from GRIKIN Advanced Material Company . The electrochemical workstation (CHI-660C), containing a standard three-electrodes system, was purchased from Shanghai ChenHua Instrument Company .The morphologies and structures of the samples were characterized by scanning electron microscopy , Raman spectrometer , UV-Visible Spectrophotometer . X-ray photoelectron spectrometer  and high resolution transmission electron microscope .2.3V2SO4H/V2O2H = 7 : 3) and heated to 120 °C for 30 min. It was then rinsed with ultrapure water and dried with nitrogen. The cleaned quartz glass was then placed in the compact etcher to etch with 30 sccm CF4 for a designated period of time. Then the plasma-etched quartz glass was placed in silica tube under a mixed atmosphere of argon  and hydrogen (40 sccm) and heated to 1030 °C. A certain amount of CH4 gas (11 sccm) was subsequently introduced into the reactor at 1030 °C for a certain period of time. Then, the silica tube was cooled to room temperature within 30 minutes. The sample was recorded as graphene grown on plasma-etched quartz glass (eQG). Graphene was grown on the surface of quartz glass for 180 min after etching for 5 min, 10 min and 15 min to confirm the effect of etching time on the growth of graphene. The effect of growth time of graphene was also studied: the growth time of graphene on quartz glass plasma-etched for 10 min was 150, 1180 and 210 min, as denoted by eQG150, eQG180 and eQG210, respectively.Graphene was grown on quartz glass substrate using the atmospheric pressure chemical vapor deposition (APCVD) method. Firstly, the quartz glass was ultrasonically washed with ethanol, acetone, and ultrapure water for 30 minutes in that order. After drying, the quartz glass was immersed in a piranha solution  finally, eQG was moved into the vacuum sputter equipment with the plasma-etched side of the quartz glass facing up. The power of the sputter equipment was 50 W and the sputtering time was 5 min. The prepared Pt nanoparticles/graphene grown on plasma-etched quartz glass is denoted as PtNPs/eQG. The samples of sputtering Pt nanoparticles on graphene grown on quartz glass at growth times of 150, 180 and 210 min were denoted PtNPs/eQG2.4For comparison, graphene grown on quartz glass (QG) was prepared by immediately placing cleaned quartz glass in silica tubes without etching under the same conditions for graphene growth.4 for 10 min labeled as platinum nanoparticles/plasma-etched quartz glass (PtNPs/eQ) were created by directly sputtering PtNPs on plasma-etched quartz glass for 5 min.As mentioned above, the cleaned quartz glass was placed in the compact etcher to etch with 30 sccm CF2.5−1, pH = 7.2) was added to a self-made electrochemical test system that includes a 25 mL beaker and a cover plate. The three-electrode electrochemical system contained a saturated calomel electrode as the reference electrode, PtNPs/eQG as the working electrode and platinum plate as the counter electrode. Then nitrogen was injected for 30 min to discharge oxygen. Cyclic voltammogram (CV) measurements were implemented from −0.3 V to 0.8 V both in the presence and the absence of 10 μM H2O2 with a scan rate of 50 mV s−1. The amperometric i–t curve was measured with 25 μL different concentrations of H2O2 at regular intervals of 50 s. Ascorbic acid (AA), dopamine (DA) and uric acid (UA) were intermittently added to detect the anti-interference performance , G (1600 cm−1) and 2D (2650 cm−1) peaks of graphene.36–38 The ratio of G peak to 2D peak was about 1 and the peak width of the 2D peak was greater than 50 cm−1, which shows that there were a few layers of graphene. The D peak at 1323 cm−1 shows the defect of graphene, which indicates that the defect structure of graphene was easier to form when quartz glass was treated by etching. In contrast, there was no obvious characteristic peak of graphene on the non-plasma-etched quartz glass substrate for the same growth time.The growth mechanism of graphene film on plasma-etched quartz glass is similar to that on heat-treated quartz glass.IG/I2D became larger  prepared by vacuum sputter equipment were characterized by HRTEM and corresponding selected area electron diffraction (SAED) pattern, as depicted in 2 phase in PtNPs/eQG. In addition, the presence of SiO2 could be further confirmed by the O 1s XPS peak at 532.8 eV, which was regarded as the oxygen species in the SiO2. As shown in Fig. S2b, PBM data was replaced with SVG by xgml2pxml:<glyph-data id="z.dbd" format="PBM" resolution="300" x-size="8" y-size="10" xml:space="preserve">00000000000000000000000000000000111111110000000011111111000000000000000000000000</glyph-data><svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="13.200000pt" height="16.000000pt" viewBox="0 0 13.200000 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>Created by potrace 1.16, written by Peter Selinger 2001-2019</metadata><g transform="translate scale" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg>C bond. The remarkable carbon peak of sp2 hybrids indicates that the sample had obvious graphite structure. The C 1s peak in the sample could be divided into four peaks, with the other three peaks at 285.8 eV, 287.6 eV and 289.1 eV representing C–C, C–O and OC–O bonds, respectively. Fig. S2c7/2 and Pt (0) 4f5/2, respectively,39 indicating the feasibility of nanoparticle sputtering technology in applications.The surface composition and element characterization of PtNPs/eQG were analyzed by X-ray photoelectron spectroscopy (XPS), as depicted in Fig. S2.180 in Fig. S3bThe effects of different growth time were investigated by comparing the Raman and UV-Vis transmission spectra of graphene grown on quartz glass with etching time of 10 min and growth time of 150 min, 180 min and 210 min. As shown in Fig. S3a,3.22O2, PtNPs/eQG150 and PtNPs/eQG210 increased current value without any peaks in this voltage window. The CV curve of PtNPs/eQG180 shows significant peaks at −0.05 V and 0.60 V in the presence of H2O2 (red solid line). This indicates the best electrochemical response electrode for H2O2 detection is PtNPs/eQG180, meaning that the optimal preparation time for graphene growth is 180 min. Therefore, the transparent electrode prepared under this condition was used as the working electrode for subsequent electrochemical performance measurements. We'll use PtNPs/eQG to denote PtNPs/eQG180.Fig. S42O2 was explored using CV tests. 2O2. The voltammogram ranged from −0.3 V to 0.8 V at a scan rate of 50 mV s−1. As shown, PtNPs/eQ and eQG had increased current value with the addition of H2O2. The CV curve of PtNPs/eQG shows higher capacitance and significant peaks of −0.05 V and 0.60 V in the presence of H2O2 (red solid line), which indicates PtNPs/eQG had an exceptional electrochemical response to low concentration of H2O2. In summary, comparing the response CV curves of different materials to H2O2, PtNPs/eQG had an impeccable electrochemical response to low concentration of H2O2.The electrochemical behavior of Pt nanoparticles/graphene grown on plasma-etched quartz glass (PtNPs/eQG) towards the sensing of H2O2, cyclic voltammetric curves with various scanning rates (40 mV s−1–180 mV s−1) were recorded in I = 0.0168 × ν + 1.1829 , indicating the dynamics control was an adsorption process.In order to demonstrate the charge transport characteristics of PtNPs/eQG in the process of electrochemical sensing H3.3i–t curve was used to test the electrochemical performance of the PtNPs/eQG toward H2O2 by adding different concentrations of H2O2 solution into the stirring system at 0.60 V. The interval was 50 seconds and H2O2 was injected twice. As shown in 2O2 increased from 10 nM to 50 μM. The results show PtNPs/eQG had excellent electrochemical performances for H2O2 detection.Amperometric 2O2 as shown in 2O2 concentration, which is in accordance of the formula I = 0.10392 + 0.00012 × c . In the range of 2–80 μM, the response current value had a strong linear relationship with the H2O2 concentration, in accordance of the formula I = 0.46593 + 0.09077 × c . In the case of a signal-to-noise ratio of 3, the detection limit was 3.3 nM, which shows the good sensitivity of PtNPs/eQG for the detection of ultralow concentration of H2O2.The response current varied with the concentration of H2O2 detection were shown in 2O2 sensors with low detection limit, short response time and wide linear range.The comparison of detection limits and linear ranges between graphene-supported PtNPs towards H2O2 detection was investigated in Fig. S5.2O2 (0.05 mmol L−1) and dopamine , ascorbic acid  and uric acid  at 0.60 V was measured. It can be seen from Fig. S52O2. The results show that PtNPs/eQG had strong anti-interference performances. This makes it an ideal candidate to be applied to the low-concentration qualitative and quantitative detection of H2O2 in the determination of actual biological samples.The selectivity of PtNPs/eQG for H4.2O2. The growth rate of graphene on quartz glass was accelerated by adding a CF4 plasma etched process. The electrochemical properties of CVD graphene without transfer and the active sites exposed of PtNPs contributed to the catalytic performance of PtNPs/eQG for H2O2 detection. The sensor has an ultra-low detection limit of 3.3 nM (S/N = 3), lower than previous similar sensors. The combination of CVD-grown graphene without transfer and in situ sputtering technology is beneficial in the practical application of non-enzymatic detection of H2O2.In conclusion, we have successfully prepared CVD-grown graphene on plasma etched quartz glass (eQG) and loaded Pt nanoparticles (PtNPs) to prepare composite materials, and used it as an independent transparent electrode for non-enzymatic detection to HThere are no conflicts to declare.RA-010-D0RA01963A-s001


Data are currently limited on the performance of SARS-CoV-2 RNA levels as predictors or surrogate markers for clinical outcomes in outpatients with mild-to-moderate COVID-19.This exploratory analysis used data from 2205 non-hospitalized adults who enrolled between August 2020 and July 2021 and participated in placebo-controlled evaluations of two monoclonal antibody (mAb) agents (bamlanivimab [n=317] or amubarvimab/romlusevimab [n=837]), and an open-label cohort of bamlanivimab recipients [n=1051] as part of the ACTIV-2/A5401 platform trial. SARS-CoV-2 RNA levels were measured in anterior nasal (AN) swabs and plasma at day 0 (pre-treatment) and AN at day 3. We fit regression models to estimate the association between RNA level or detection and subsequent hospitalization/death within 28 days of enrollment.10 copies/mL [cp/mL]) and mAb (2.3 vs 4.9) groups. For placebo recipients, higher Day 0 AN RNA was associated with an increasing risk of hospitalization/death, ranging from 3% to 16% for < 2 and ≥ 6 log10 cp/mL, respectively. Although only 1% had quantifiable plasma SARS-CoV-2 RNA, there was a similar trend for day 0 plasma RNA: 5% hospitalizations/death for undetectable RNA, 16% for detectable but not quantifiable RNA, and 80% for ≥ 2 log10 cp/mL. Among 485 placebo recipients with days 0 and 3 AN RNA results, the risk of subsequent hospitalization/death was highest among those with ≥ 5.0 log10 cp/mL at both days  and lowest for those with unquantifiable levels at both days . Higher AN RNA at day 3 (adjusted for day 0 RNA) was associated with subsequent hospitalization/death among placebo recipients (relative risk (RR): 1.4 per log10 cp/mL; 95%CI: 1.0, 2.1), but not mAb recipients .One-hundred four participants (53/571 [9%] on placebo and 51/1634 [3%] on mAb) died or were hospitalized through day 28. Median AN RNA levels were lower at day 3 compared to day 0 in both placebo |Merck: Advisor/Consultant|Ridgeback Biopharmaceuticals: Research funding provided to the University of North Carolina|Roche: Advisor/Consultant|Syneos: Adjudication committee (Influenza) Paul Klekotka, MD, PhD, Eli Lilly: Employee|Eli Lilly: Stocks/Bonds David A. Margolis, MD MPH, Brii Biosciences: Stocks/Bonds David A. Wohl, M.D., Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Lilly: Grant/Research Support|ViiV: Advisor/Consultant|ViiV: Grant/Research Support Eric S. Daar, M.D., Gilead: Advisor/Consultant|Gilead: Grant/Research Support|Merck: Advisor/Consultant|ViiV: Advisor/Consultant|ViiV: Grant/Research Support Davey M. Smith, M.D., M.A.S., Arena Pharmaceuticals: Advisor/Consultant|Bayer Pharmaceuticals: Advisor/Consultant|Brio Clinical.: Advisor/Consultant|Fluxergy: Advisor/Consultant|Kiadis: Advisor/Consultant|Linear Therapies: Advisor/Consultant|Matrix BioMed: Advisor/Consultant|Model Medicines: Advisor/Consultant|Signant Health: Advisor/Consultant|VxBiosciences: Advisor/Consultant Judith S. Currier, M.D., MSc, Merck: Advisor/Consultant.