Novel biogenic silver nanoparticles as invigorated catalytic and antibacterial tool: A cleaner approach towards environmental remediation and combating bacterial invasion

Abstract

One pot synthesis of biogenic novel silver nanoparticles (AgNP) was accomplished using Syzygium cumini (S.cumini) fruit extract. Biomolecules present in the phytoconstituent possessed strong antioxidant activity, which leads to the successful reduction of silver (Ag+) ions into (Ago) nuclei. The effect of essential process parameters on the characteristic properties of the AgNP was intrigued via UV–Vis spectroscopy and they were optimized using one factor at a time (OFAT) based approach. The formation of nanoparticle was substantiated by the reddish brown color of the colloidal suspension, which on further UV–Vis analysis resulted in the generation of characteristic SPR absorption band centered at 422 nm. Kinetic investigations revealed a tri-phasic growth pattern with a rate order constant of 0.085 min−1. The obtained value of rate constant indicates towards the spontaneous formation of AgNP.Further, morphological investigations using HR-TEM, EDS and DLS revealed that the synthesized particles were uniformly spherical (6.457), monodisperse (PDI = 0.522), chiefly composed of elemental silver (3 keV, L series, 88.19 (wt %) normalized) and possess high surface charge (−22.26 mV). ATR-FTIR spectroscopy confirmed the capping of phytoconstituents on the corona, which provided stability to AgNP. AgNP acted as an excellent catalyst (2.88 eV band gap energy) and mediated the NaBH4 based reduction of model dyes. Further, promising antibacterial activity was depicted by AgNP against Gram (−) ve bacterial strains.