Green biosynthesis of ZnO nanoparticles using Vitex negundo L. extract: Spectroscopic investigation of interaction between ZnO nanoparticles and human serum albumin.

Zinc oxide nanoparticles are widely used as an important kind of biomaterials. The biocompatibility of nanoparticles is important for specific biomedical applications. In this present investigation, ZnO NPs were synthesized via greener method using Vitex negundo L. extract and characterized by XRD, UV-DRS and DLS analysis. The UV-visible absorption and fluorescence spectroscopic studies were performed to investigate the binding interaction between HSA and ZnO NPs. The Stern-Volmer constants (KSV), quenching rate constants (kq), number of binding sites and binding constants were calculated from relevant fluorescence quenching data. Moreverer circular dichroism (CD) spectroscopy used to study the conformational changes of protein in the presence of ZnO NPs.