Sol-gel Immobilized Horseradish Peroxidase Modified Carbon Paste Electrode towards the Determination of Hydroquinone in Non-Aqueous Solvents: A Voltammetric Study

A new type of biosensor for hydroquinone (H2Q) has been synthesized based on the carbon paste electrode (CPE) immobilized with Horseradish Peroxidase (HRP), through silica sol-gel (SiSG) entrapment. The electrochemical properties of biosensor are characterized by employing the electrochemical methods like cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The proposed biosensor show high sensitivity in determination and rapid response towards H2Q under optimum conditions. The electrocatalytic response of H2Q was detected in methanol, ethanol, 2-propoanol, 1 butanol and acetone. The good results were obtained in ethanol as a solvent and acetate buffer solution (ABS) as supporting electrolyte, the experiments were carried out in combination of these two media. The anodic peak current of H2Q shows a linear relation with concentration range of 5×10-6 M to 10×10-4 M. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 1.5×10-6 M and 5.0×10-6 M respectively. The electrochemical impedance spectroscopy (EIS) result confirmed the occurrence of rapid electron transfer at HRP-SiSG/CPE. Moreover the stability, reproducibility, and repeatability of the biosensor were also studied. The proposed sensor was successfully applied for the determination of H2Q in real samples and the result were found to be commensurate.