Study of the antibacterial and catalytic activity of silver colloids synthesized using the fruit of Sapindus mukorossi

Abstract

Green synthesis of silver nanoparticles has been demonstrated using an aqueous extract of the pericarp of Sapindus mukorossi fruit as a reducing agent as well as a stabilizer. The reducing power of the extract has been evaluated by Cyclic Voltammetry (CV) experiments. The as-synthesized colloid is highly stable and the particles remain dispersed even after one year of storage. The existence of metallic silver nanoparticles was confirmed by UV-Vis spectroscopy and selected area electron diffraction (SAED) patterns obtained from high resolution transmission electron microscopic (HRTEM) analysis. TEM study shows that the particles are almost spherical with an average diameter of 3.32 ± 0.58 nm. The as-synthesized silver colloid (Ag-colloid) exhibits antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The catalytic efficiency of the Ag-colloid has also been evaluated and reported in terms of the catalytic activity parameter (κ) and turn over frequency (TOF) against the degradation of the common environmental pollutants 4-nitro phenol and Eosin blue.