Green synthesis of silver nanoplates using the special category of plant leaves showing the lotus effect

Abstract

This paper reports the first ever green synthesis of silver nanoplates using plant leaves having the special feature of showing the lotus effect. Eichhornia crassipes and Colocasia esculenta plant leaves were chosen for the purpose. The aqueous leaf extract of these plants was used as a reducing as well as stabilizing agent in the hydrothermal synthesis of silver nanoplates using silver nitrate as the precursor. Well dispersed silver nanoplates were formed. The appearance of two SPR (Surface Plasmon Resonance) bands corresponding to in-plane and out of plane vibration confirmed the formation of anisotropic nanostructures. The blue shift in peaks of the nanostructures in UV-visible spectra gave information about the stability of the nanoplates with time. Dynamic Light Scattering (DLS) and powder XRD were used to evaluate the ultimate average diameter and crystal structure of these nanostructures respectively. FESEM/EDX and HRTEM/SAED images also confirmed the formation of silver nanoplates. The FT-IR spectra helped to identify the reducing and stabilizing component of plant leaves extract in the formation of 2-D nanostructures. Preliminary antibacterial activity was examined using these nanoplates. A significant zone of inhibition was observed for S. aureus, a Gram positive bacterium.