Electrochemical and computational study of copper histidine complex via cyclic voltammetry

Summary: L-Histidine regulates body function and involve in the synthesis of hemoglobin, repairing of tissues and strengthens of immune system. In this study, Cyclic Voltammetry (CV) is used with 0.1 M Potassium Chloride as a supporting electrolyte to determine the accurate metal ligand ratio between Cu+2 and L-Histidine. In CV potential window is set between +0.6 to -0.4V to record the Voltammogram. Voltammograms were recorded by varying scan rate from 50mV/s to 300mV/s. Cyclic Voltammetry is used to analyzed the interfacial performance of the complex and repeated Cyclic Voltammograms (07 cycles) were recorded at Glassy Carbon Electrode (GCE), that shows no change in peak current intensity of both anodic and cathodic peak. Further, neither pre nor any post peak was observed. These interpretation express that reactant and product are not involve in the adsorption-desorption process at the surface of Glassy Carbon Electrode (GCE). These remarks suggest that it is diffusion controlled process in the above mentioned system. The interaction of Cu+2 and L-Histidine were not reported before through Cyclic Voltammetry. Furthermore, in this study structure of Cu+2 vs. L-Histidine complex is investigated from a theoretical perspective. Optimization of Cu+2 vs. L-Histidine complex was carried out by DFT method and result verifies that stable structure of Cu+2 vs. L-Histidine complex exist as square planar structure in 1:2 ratio respectively. The computed structure has correlation with experimental results and Voltammogram of 1:2 ratio complex of Cu+2 vs. L-Histidine suggested that it exist in Square planar geometry. (author)