Multifunctional Two-Dimensional Reduced Graphene Oxide Thin Film for Gas Sensing and Antibacterial Applications

Multifunctional luminescent chemically reduced graphene oxide (rGO) thin film was fabricated by hydrazine hydrate vapor reduction of graphene oxide (GO) thin film on quartz substrate. Detailed morphogenesis studies have been carried out through various microscopic techniques to explore the surface morphology, uniformity, thickness of the film. The photoluminescence spectroscopy analysis confirms the film quality and extended graphitization of the rGO thin film. Moreover, the electrical and gas sensing properties of the rGO thin film are extensively monitored. It is observed that rGO exhibits good electrical conductivity similar to 104 S m(-1) (1.04 S cm(-1)) at room temperature and good gas sensing properties for variable concentrations of Cl-2 and NO2 gases. The percentage response for NO2 and Cl-2 gases at a fixed 50 ppm concentration are found 27% and 54%, respectively. Additionally, as-synthesized GO and rGO thin films show excellent bacterial toxicity for both Gram +ve (B. cereus) and Gram -ve (E. coli) models of bacteria, which implies that GO and rGO can be used as effective antibacterial coatings. The colligative fast gas sensing response and good antibacterial property of rGO thin film suggest that this material could be an ultimate choice for next generation smart, portable two dimensional (2D) gas sensors as well as in various biomedical applications.