Facile synthesis of tunable silver nanostructures for antibacterial application using cellulose nanocrystals

In this study, we report a facile and environmentally friendly strategy for synthesis of well dispersed and stable silver nanostructures using cellulose nanocrystals in aqueous solution without employing any other reductants, capping or dispersing agents. Importantly, it is feasible to adjust the morphology of the silver nanostructures by varying the precursor AgNO3 concentration. Silver nanospheres were formed when the AgNO3 concentration was 0.4 mM, while the dendritic nanostructures predominated when the AgNO3 concentration was increased to 250 mM. The antibacterial activity of the two different silver nanostructures against Escherichia coli and Staphylococcus aureus was characterized. Dendritic nanostructure showed a better antibacterial activity than that of silver nanosphere. The approach presented in this paper offers a very promising route to noble metal nanoparticles using renewable reducing agents.