Convenient process to synthesize reduced needle platy graphite silver nanocomposite: A prospective antibiotic against common pathogenic microorganisms in the environment

Metal nanoparticles (NPs) have earned keen interest due to differences in their physical and chemical properties according to their size. In this study, reduced needle platy graphite silver (rNPG/Ag) nanocomposite has been prepared using natural vein graphite by in-situ chemical reduction method. We found an extraordinary behavior of this rNPG/Ag composite as an antimicrobial agent for pathogenic microorganisms in the environment; Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. Further, above pathogens can build a resistivity against bare silver NPs as well as the rNPG. This is due to the reduction of permeability and enzyme detoxification or efflux of the toxic metal ions. Also, the antibacterial activity of rNPG can be inhibited by poor penetration into the cell as well as the poor dispersion of the material in the medium. On the other hand, the rNPG/Ag composite is used, the Ag nanoparticles embedded with rNPG sheets can enter into the microbial cell through membrane proteins by simple diffusion or endocytosis which inhibits the microbial activity. This penetration of Ag is facilitated by the rNPG sheets as it contributes to the stability and the nano-sized formation of Ag. Our results conduct to develop broad perspective antimicrobial agent using a straightforward and low-cost chemical route.