Plant Mediated Green Synthesis of Silver Nanoparticles Using Tecomella undulata Leaf Extract and Their Characterization

Green synthesis of silver nanoparticles (AgNPs) was carried out using aqueous extract of Roheda (Tecomella undulata) at 60 ℃ in orbital shaking incubator. The variation in pH values and colour changes were observed within few minutes during reduction of silver nitrate (0.1 to 1 mM final concentration) in presence of plant extract and the capping of synthesized stable silver nanoparticles. The UV-Vis spectra of reaction mixture at different time intervals were recorded to monitor the formation of nanoparticles. The maximum absorption peak was observed near 430 nm indicating the formation of AgNPs. The particle size distribution was analysed through dynamic light scattering (DLS) and it was found that the peaks at 5.85 nm and 77.48 nm. Polydisperse Index (PDI) of synthesized AgNPs is 0.378 indicating that nanoparticles are stable even after nine months storage and uniform size range. The stability of biogenic silver nanoparticles was monititored through zeta potential measurement. The surface properties and size of the nanoparticles were studied through scanning electron microscopy and atomic force microscopy. The purity of the synthesized nanoparticle was confirmed by electron dispersive X-ray spectroscopy (EDS). Atomic force microscopy images indicated that height of the particle ranges from 3-18 nm. The results of various techniques indicated that these are silver nanoparticles synthesized using leaf extract of Tecomella undulata.