Highly stable silver nanoparticles synthesized using Terminalia catappa leaves as antibacterial agent and colorimetric mercury sensor

[Display omitted] •Green synthesis route for AgNPs using agrowaste – T. catappa leaves.•AgNPs used as colorimetric sensors for mercury.•AgNPs exhibit good antibacterial activity.•Crystalline, monodispersed, quasi-spherical shaped AgNPs of size∼11nm.•Stable AgNPs capped with phytocomponents and zetapotential of −36.7mV. Silver nanoparticles (AgNPs) were synthesized using the aqueous extract of an agrowaste: Terminalia catappa leaves. The AgNPs were characterized using UV–VIS spectroscopy, Transmission electron microscopy, Scanning electron microscopy, Fourier Transmission Infrared spectroscopy and Dynamic light scattering analysis. AgNPs were monodispersed, crystalline, quasi-spherical with average size of∼11nm and were encapsulated with capping agents present in the extract. The AgNPs were stable with the zeta potential value of −36.7mV. These AgNPs exhibited significant antibacterial activity against water borne pathogens and could be used as colorimetric sensors for the detection of trace levels of mercury, indicating their multifaceted application in antibacterial coating, water treatment and as colorimetric mercury sensors. The overall synthesis process emphasizes on the agrowaste utilization for the “green” synthesis of AgNPs.