Antibacterial activity of reduced graphene oxide prepared by microbe

Abstract

In previous work, we successfully bioreduced graphene oxide (B-rGO) utilizing organisms, but the antibacterial properties of B-rGO are still unknown. In this study, Escherichia coli (E. coli) was used as a test target and the antibacterial activity of B-rGO was compared to that of commercial reduced graphene oxide (C-rGO), in order to understand its toxicity. Data from levels of extracellular lactate dehydrogenase (LDH), and intracellular reactive oxygen species (ROS) content demonstrate that cell membrane stress and oxidative stress play a role in this antibacterial process. However, when the concentration of co-existing B-rGO was 50.0 mg/L, E. coli damaged easily, the LDH release concentration was 98.75 U/L, the ROS fluorescence signal was 57.75/106 cells, and the phenomenon known as ‘wrapping’ occurred. Indicated here is that B-rGO does indeed demonstrate very good antibacterial activity as evidenced when using Scanning Electron Microscopy (SEM). Meanwhile, numerous oxygen-containing functional groups existed on the surface of B-rGO as confirmed by Fourier transform infrared spectroscopy (FTIR). The power-time curve of microcalorimetry and flow cytometry analysis confirmed that the antibacterial activity of B-rGO was inadequate when compared to that of C-rGO. Despite E. coli mortality being dosage-dependent for both B-rGO and C-rGO, this implies that B-rGO does in fact achieve good biocompatibility. The outcomes reveal that B-rGO has great potential for environmental remediation.