Mussel-inspired synthesis of antibacterial paper based on silver nanoparticles

Abstract

In this research, we developed a bio-inspired strategy for immobilizing silver nanoparticles (AgNPs) onto cellulose paper to constract antibacterial paper. We exploited interesting dopamine chemistry to achieve in situ reduction of Ag+ salt to AgNPs and deposition of AgNPs on the paper surface. Firstly, the cellulose paper surface was chemically modified with carboxylic acid groups by reaching it with succinic anhydride. Next, the carboxylic groups of the surface were reacted with the –NH2 group of dopamine in a buffer to introduce the dopamine molecules. The covalently attached dopamine molecules on the paper surface resulted in rapid and efficient immobilization of AgNPs from the solution of AgNO3. The loading and the robustness of AgNPs into paper matrix were quite excellent. The paper showed excellent antimicrobial activity against Vibrio pharahaemolyticus strain 2A1, Vibrio pharahaemolyticus strain 2A2, Enterococcus faecalis strain FF11, Enterococcus faecalis strain F1B1, Serratia marcescens strain 4V3 which are highly virulent and resistant to multiple antibiotics. The paper also showed antifungal activity against extremely virulent “wheat blast” disease causing fungal species. Phytotoxicity test reveals that the synthesized AgNP-paper does not cause any harm to seed germination and plant leaves cells. The paper was characterized by x-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Atomic-force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. From the SEM and thermal study, it was found that the deposition of AgNPs into paper matrix was time dependent. The AgNPs which is deposited onto paper matrix had an average size of 50-60 nm and were uniformly distributed on the every part of the paper surface. The XPS analysis revealed that the binding energy peaks at 366.0 and 372.0 KeV correspond to Ag (0). No additional Ag compounds were detected during the XPS analysis.