Hydrogen Peroxide Impedimetric Detection on Poly-Ortho-Phenylenediamine Modified Platinum Disk Microelectrode

This work describes the development of hydrogen peroxide detection based on Poly-ortho-phenylenediamine modified Platinum disk microelectrode (50 μm in diameter). The electrochemical performances of H2O2 detection were studied using Chronoamperometry, Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) techniques in Phosphate Buffer Solution (PBS) pH 7.4. Effect of potential, electrode size, and various concentrations of H2O2, among others, were investigated by tracking the impedance changes at a specific perturbation frequency. To obtain the Charge transfer resistance (Rct) values, a modified Randles Equivalent Circuit was modelled and fitted to Nyquist Plot. Then, this sensor was further applied in the detection of H2O2 in antiseptic mouthwash with percent recovery of 97 % ± 0.14 (x103 kΩ). (author)