Functional silver nanoparticles as broad-spectrum antimicrobial agents

Abstract

Drug resistance has become a serious global concern, and therefore developing a new antibacterial agent that can fight drug-resistant bacteria without generation of resistance is urgent. Herein, we synthesize indole functionalized silver nanoparticles (Ag NPs) through a simple one-pot method to fight drug-resistant bacteria. When silver nanoparticles are modified with 5-nitroindole and tryptophan, these two silver nanoparticles (5NI-Ag NPs and Try-Ag NPs) exhibit excellent antibacterial activities against both Gram-positive and Gram-negative bacteria (S. aureus and E. coli). In particular, Try-Ag NPs exhibit better antibacterial activity against both normal bacteria and drug-resistant bacteria with a low MIC of 6 μg mL⁻¹ for E. coli and 8 μg mL⁻¹ for S. aureus, respectively. Moreover, it is not easy for bacteria to generate resistance toward Try-Ag NPs. In conclusion, our research provides a possibility for developing new antibacterial materials to fight DR bacteria by modifying silver nanoparticles with small molecule ligands.