Electrochemical Studies of a Novel Biosensor Based on the CuO Nanoparticles Coated with Horseradish Peroxidase to Determine the Concentration of Phenolic Compounds

The present work is an attempt to design new electrochemical biosensor that easily determines the concentration of phenolic compounds in water and wastewaters. It is well-known that enzymes can add selectivity towards one or limited number of compounds. Thus, in the present study, horseradish peroxidase (HRP) was coated on CuO nanoparticles and immobilized on the electrode using a thin polymeric film. The electrochemical studies of modified electrode were carried out by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The voltammetric and EIS results confirm the possibility of HRP direct electron transfer at CuO nanoparticles. Our results revealed that the modified electrode can be used to determine the phenol concentration in the standard solutions and real samples. The present biosensor has good relative standard deviation (RSD% = 7%) and detection limit (DL of 0.1 mu M), in addition to high stability.