GOLD NANOPARTICLES CAN INHIBIT ANTIMICROBIAL PROPERTY OF CHITOSAN

Gold nanoparticles (AuNPs) have attracted increasing interest in diagnosis and therapy of disease, being widely used in biosensors, cancer cell imaging, photothermal therapy, drug delivery and as antimicrobial agents. Using a well diffusion method and an evaluation of bacterial growth in liquid media we assessed the antimicrobial properties of chitosan capped AuNPs with different sizes and concentrations. The obtained data showed that chitosan capped Au NPs and chitosan inhibited the growth of Escherichia coli and Staphylococcus aureus. The inhibition effect was due more likely to the antimicrobial properties of chitosan rather to the AuNPs. Our results suggest that Au NPs can inhibit the antimicrobial activity of chitosan, regardless of sizes and concentrations used, in the case of both tested bacteria.