A facile and green approach for the fabrication of nano-biocomposites by reducing silver salt solution into silver nanoparticles using modified carboxymethyl cellulose for antimicrobial potential

Biopolymers represent an excellent alternative to their synthetic analogues for use as natural stabilizers in the development of unique metal nanoparticles, owing to their attractive properties including low cost, environmentally friendly nature, renewability, biodegradability and biocompatibility. Herein, a new, straightforward chemical approach was investigated to synthesize Ag nanoparticle-decorated sulfonated carboxymethyl cellulose (AgNPs/S-CMC) nano-biocomposite materials with strong antimicrobial properties. Sodium carboxymethyl cellulose (CMC) was firstly chemically modified into sulfonated CMC (S-CMC), which was used as an environmentally friendly stabilizer and a nonhazardous reducing agent towards the fabrication of AgNPs in aqueous solution. Four types of AgNPs/S-CMC nano-biocomposites were fabricated to investigate the effect of the concentration of the S-CMC stabilizing/reducing agent on the fabrication of AgNPs, the physiochemical properties and the antimicrobial activity performance. The fabrication of AgNPs was investigated by UV-Vis spectra through characteristic surface plasmon resonance peak analysis, and the chemical structures were characterized by FTIR, FE-SEM, EDAX and XRD analyses. The synthesized AgNPs/S-CMC nano-biocomposites were tested as a potential antimicrobial agent, confirmed by the agar diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) analysis against Gram-positive B. subtilis and Gram-negative E. coli bacterial strains. The obtained results confirm that the proposed nano-biocomposites exhibit excellent antimicrobial activity against both Gram-positive and Gram-negative bacterial strains.