Preparation of ZnO@SiO2-n-propyl-NH2 functionalized with benzoylthiourea-Cu(II) for the simultaneous detection of hydroquinone and catechol

This study presents the synthesis of nanocomposites consisting of ZnO@SiO2-n-propyl-NH2 functionalized with benzoylthiourea-Cu(II) using the sol-gel method. The electrochemical properties of the composite were evaluated for the detection of catechol (CC) and hydroquinone (HQ) through differential pulse voltammetry (DPV). The electrochemical performance of the sensor was evaluated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The modified electrode exhibited excellent electrocatalytic activity and reversibility towards the oxidation of both catechol (CC) and hydroquinone (HQ) in a 5x10-8M acetate buffer solution (pH = 7.0). The relationship between the oxidation peak current of CC and its concentration was found to be linear in the dynamic range from 2.5 x 10-8 to 1.5 x 10-7 M, while a similar linear relationship was observed for the oxidation peak current of HQ within the range of 2.5 x 10-8 to 1.5 x 10-7 M. The detection limits (S/N = 3) for CC and HQ were determined to 5 10-8 M.