Antimicrobial carbon-dot–stabilized silver nanoparticles

Abstract

Bacterial infections pose an emerging threat to human health. The overuse of various antibiotics is unavoidable causing antibiotic resistance. Silver nanoparticles (AgNPs) are excellent candidates for combating pathologies and avoiding antibiotic resistance. The interaction of nanoparticles and bacteria depends on the surface charge and chemical group of the ligands. Herein, using carbon dots (CDs) with abundant chemical groups as ligand, AgNPs were synthesized by reducing the mixture of CDs and Ag ions with NaBH₄. Carbon-dot–stabilized silver nanoparticles (CD–AgNPs) possess good antibacterial activity. The stable CD–AgNPs increase the antibacterial activity compared with AgNPs without CDs. The minimum inhibitory concentration (MIC) of the CD–AgNPs was 100 μg mL⁻¹ with 0.613 μg mL⁻¹ Ag. Due to inhibiting the growth of six species (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Vibrio parahemolyticus, and Shigella castellani), the CD–AgNPs possess broad-spectrum antibacterial activity. The obtained CD–AgNPs are promising to develop a good antibacterial agent for application in medical and food fields.