Rapid production of silver nanoparticles at large-scale using gallic acid and their antibacterial assessment

Gallic acid (trihydroxybenzoic acid) an abundantly available plant phenolic bioresource was utilized to establish a greener production of smaller sized (8 +/- 4 nm) stable silver nanoparticles (AgNPs), without any waste byproducts. To improve quality of AgNPs, different concentrations of gallic acid (ranging from 2.50 to 11.25 mM), furthermore reaction kinetics was remarkably improved up to fraction of minute using gallic acid:NaOH ratio. Highest transformation (95%) of initial Ag ions (250, 500, and 1000 ppm) into highly dispersed AgNPs was successfully achieved using low concentration of gallic acid (9.375 mM) without affecting the quality of AgNPs. The gallic acid bioprocess seems to be most suitable for the exponential manufacturing, it would play an important role to resolve the scale-up problem with low volume. Smaller AgNPs showed the minimum inhibitory concentration (MIC) at about 20 and 50 ppm against gram negative and gram positive bacterial cultures, respectively. (C) 2015 Elsevier B.V. All rights reserved.