Preparation of green silver nanoparticles with high antibacterial ability using N-maleoyl chitosan and montmorillonite

Abstract

The antimicrobial properties of silver nanoparticles (AgNPs) are significantly affected by their size. In our previous study, we synthesized low-toxicity AgNPs using chitosan derivatives. As chemical reductants and stabilizers were not used in the preparation process, the toxicity of the products was very low. However, the size of the as-obtained nanoparticles was relatively large (100–150 nm). In this study, we used N-maleoyl chitosan and montmorillonite to prepare small-sized green AgNPs and investigated the effect of the reaction system viscosity and crystal growth space on the formation of small-sized nanoparticles. We found that increasing the viscosity of the reaction system or controlling the crystal growth space was conducive to the green preparation of small-sized AgNPs. The prepared AgNPs had higher antibacterial ability and lower cytotoxicity. To the best of our knowledge, this is the first time that AgNPs with such a small size (less than 5 nm) have been prepared using a simple and completely green method.