Multi-functionalized biosensor at WO3–TiO2 modified electrode for photoelectrocatalysis of norepinephrine and riboflavin

The titanium dioxide (TiO2), mixed different ratio tungsten oxide (WO3) hybrid film WO3–TiO2 was prepared on indium tin oxide (ITO) electrode. TiO2:WO3 = 9:3 (v/v) group current value was 5.44 mA under irradiation conditions. This group showed highest photocatalytic activity than others, we selected to optimization us in follow-up experiment. In this paper, the electrochemical oxidation and reduction of norepinephrine (NEP) and riboflavin (Vitamin B2) as multi-functionalized biosensor. The TiO2 exhibited a promising enhanced photoelectrocatalytic activity toward analytes. Surface morphology of the modified electrode using atomic force microscopy (AFM), which revealed that WO3 and TiO2 were coated on ITO. The presence of TiO2 enhances the loaded and stability. Electrochemical impedance spectroscopy (EIS) applied diffusion coefficient values and some information about the kinetics of electron transfer during the redox reactions. Cyclic voltammograms (CVs) and differential pulse voltammetry (DPVs) were used for the determination of analytes. DPVs not only increased the electrocatalytic current linear concentration range, also lowered the overpotential to oxidation or reduction the interferences in the measurements. We simulated more complex system if both norepinephrine and riboflavin are present simultaneously. It also exhibited oxidation and reduction peaks for norepinephrine injection and B complex tablet's real samples determination in pH 7.0 at WO3–TiO2 modified electrode.