Preparation and optimization of antibacterial activity of graphene oxide silver nanocomposite

Abstract

Graphene oxide (GO) was prepared using simplified Hummer's method, and GO-silver nanocomposite (GOAg) was prepared by microwave irradiation. The synthesis aims to decorate silver nanoparticles (AgNPs) on the surface of graphene oxide (GO) to enhance silver nanoparticle performances. The nanocomposite was characterized by using ultraviolet-visible spectrophotometry (UV-Vis) and fourier transform infrared (FTIR). Antibacterial activity of the nanocomposite was investigated using the disk diffusion method where several parameters such as GOAg loading (10%, 20%, and 30%), bacterial suspension concentration (1.5 and 3.0 × 108 CFU/ml), and incubation temperature (30 and 35 °C) were varied. The antibacterial study was tested against one gram-negative bacteria, which is Escherichia coli ATCC 8739 (E. coli) and Gram-positive bacteria were Staphylococcus aureus (S. aureus) Lactobacillus Plantarum BD 8913C (L. Plantarum), and Bacillus subtilis (B. Subtilis). The results reveal that E.Coli were more susceptible against GOAg nanocomposite at 30°C; meanwhile, S.Aureus, L.Plantarum were more susceptible to incubation temperature at 35°C. The results also indicate that the GOAg nanocomposite also shows a promising inhibition zone with increasing bacterial suspension and disclosing its potential to be used in many other applications.