Comparative study of synthesized silver and gold nanoparticles using leaves extract of Bauhinia tomentosa Linn and their anticancer efficacy

Nanotechnology is an emerging field in science and technology, which can be applied to synthesize new materials at the nanoscale level. The present investigation aimed at comparing the synthesis, characterization and in vitro anticancer efficacy of synthesized silver and gold nanoparticles using leaves extract of Bauhinia tomentosa Linn. Silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using aqueous extract of leaves with solution of silver nitrate (AgNO₃, 1 mM) and chloroauric acid (HAuCl₄?3H₂O, 1 mM), respectively. The synthesized nanoparticles were characterized using UV–visible spectrophotometry, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive analysis of X-rays, X-ray diffraction, thermogravimetric analysis and cyclic voltammetry, which confirmed the reduction of Ag⁺ ions to Ag⁰ and Au³⁺ ions to Au ⁰ . The in vitro anticancer efficacy of AgNPs, AuNPs and aqueous extract of leaves confirmed by MTT assay exhibited IC₅₀ concentrations of 28.125, 46.875 and 50 μg ml^?1 for lung A-549 cells, 103.125, 34.375 and 53.125 μg ml^?1 for HEp-2 cells and 62.5, 23.4 and 13.26 μg ml^?1 for MCF-7 cells, respectively. The concentrations indicate that both silver and gold nanoparticles as well as aqueous extract of leaves exhibited high anticancer efficacy.