Simultaneous electrochemical detection of antioxidants Hydroquinone, Mono-Tert-butyl hydroquinone and catechol in food and polymer samples using ZnO@MnO2-rGO nanocomposite as sensing layer

A sensing layer containing ZnO@MnO2-rGO nanocomposite was used for modification glassy carbon electrode (GCE) for monitoring some antioxidant molecules including Hydroquinone (HQ), Mono-Tert-butyl hydroquinone (MTBHQ) and catechol (CC). The resulting ZnO@MnO2-rGO/GCE exhibited significant electrocatalytic activities toward the electro-oxidation of MTBHQ, HQ, and CC in the linear range (LR) of 0.008 to 10 µM and 10 to 350 µM for MTBHQ, 0.008 to 10 µM and 10 to 320 µM for HQ, 0.008 to 8 µM and 8 to 330 µM for CC with the limits of detection (LOD) of 0.0011, 0.0012 and 0.001 µM, respectively by differential pulse voltammetric (DPV). The prepared sensor has been used to analysis of different real samples containing target analytes with satisfactory results. Based on the percentage of recovery range (95.5-104.4 %), Relative standard deviation (RSD%, below 3.51 %), and the obtained data from the HPLC method, the presented method are accurate with acceptable precision.