Exploring the synergistic potential: the integration of electrolytically synthesized silver nanoparticles into graphene oxide for enhanced antimicrobial activity

Currently, one of the main global issues is the growing resistance of microorganisms to antibiotics. For this reason, in recent years, research has focused on the continuous search for new materials that can enhance antibacterial efficiency. One material that has attracted attention in various fields of science is graphene oxide (GO), which has been used as a support to disperse numerous nanoparticles. This is due to the functional groups distributed on its surface, which act as reactive sites that promote nucleation and growth. The main objective of this work was to improve the antibacterial capacity of GO through functionalization with silver nanoparticles (GO–Ag). GO was synthesized using the modified Hummers method, and silver nanoparticles (AgNPs) were synthesized using an optimized electrolytic method. Through transmission electron microscopy (TEM), AgNPs with an average diameter of 10.8 nm were observed to be anchored to the GO sheets, which was corroborated by absorption spectroscopy. The antimicrobial capacity of AgNPs, GO, and GO–Ag was quantitatively determined using the plate microdilution method against the bacteria Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 29213), and Enterococcus faecalis (ATCC 29212). GO did not exhibit antibacterial activity even at the highest concentration used. In contrast, the strains showed high sensitivity against GO with silver nanoparticles; additionally, these results proved to be more efficient than those obtained with AgNPs alone. Therefore, the obtained data indicated that the functionalization of GO with silver nanoparticles increases the bactericidal capacity of the material and could be considered a novel option for the development of potential antibacterial agents. Graphical abstract