Synthesis and Stabilization of Tellurium Nanoparticles with Soap Nut Extract as a Capping Agent and Evaluation of Their in Vitro Antibacterial Efficacy

Tellurium (Te) is an industrial and environmental contaminant.Due to their powerful antibacterial characteristics, tellurium nanoparticles (TeNPs) are prominent in biology.This study shows that soap nut (Sapindus mukorossi) fruit extract can easily synthesize and stabilize TeNPs.Ascorbic acid lowered sodium tellurite while SNF extract gradually capped and stabilized it.Studies on SNF-TeNPs included UV-visible, hydrodynamic size, zeta potential, Raman, and TEM analysis.We compared the properties of TeNPs stabilized by bovine serum albumin (BSA-TeNPs), a typical capping agent.The SNF-capped TeNPs produced were stable at all pH levels, with greater stability at pH 6 and 7.Both SNF and BSA-TeNPs were better stored at 4 °C.SNF-TeNPs had a hydrodynamic size of ∼227 nm and BSA-TeNPs ∼340 nm, with distinct TEM morphologies: nanoneedles for SNF-TeNPs and nanospheres for BSA-TeNPs.Both SNF and BSA-TeNPs were assessed for antibacterial activity using disk diffusion assay at doses of 20, 50, and 100 µg/mL.Compared to BSA-TeNPs, SNF-TeNPs shown superior action against Escherichia coli and Staphylococcus aureus.These results indicate that soap nut extract may stabilize and maintain TeNPs in various physicochemical settings and be employed as a novel antibacterial system with a better knowledge of their mode of action.