Multi-spectroscopic and computational evaluation on the binding of sinapic acid and its Cu(II) complex with bovine serum albumin

•Binding interaction of sinapic acid and its Cu2+ complex with BSA was investigated.•A static quenching mechanism was involved in the interaction process in both cases.•Binding and thermodynamic parameters were evaluated for both the systems.•In both systems, site I (subdomain IIA) was the preferred binding site.•Biological assay was performed to compare the anti-oxidant activities of two compounds.