Banana peel extract mediated novel route for the synthesis of silver nanoparticles

Bio-inspired silver nanoparticles were synthesized with the aid of a novel, non-toxic, eco-friendly biological material namely, banana peel extract (BPE). Boiled, crushed, acetone precipitated, air-dried peel powder was used for reducing silver nitrate. Silver nanoparticles were formed when the reaction conditions were altered with respect to pH, BPE content, concentration of silver nitrate and incubation temperature. The colorless reaction mixtures turned brown and displayed UV-visible spectra characteristic of silver nanoparticles. Scanning electron microscope (SEM) observations revealed the predominance of silver nanosized crystallites after short incubation periods. When the reaction mixtures were incubated for 15 days, some micro-aggregates were also observed. Energy dispersive spectrometer (EDS) studies and X-ray diffraction analysis confirmed the presence of silver nanoparticles. Fourier transform infra-red spectroscopy (FTIR) indicated the role of different functional groups (carboxyl, amine and hydroxyl) in the synthetic process. These silver nanoparticles displayed antimicrobial activity against fungal as well as bacterial cultures. (C) 2010 Elsevier B.V. All rights reserved.