Preparation of molecularly imprinted electrochemical sensors for selective detection of hydroxyl radicals based on reduced graphene oxide nanosilver (rGO/AgNPs) composites

An electrochemical sensor for selective detection of hydroxyl radicals (OH) has been developed, which is based on silver nanoparticles and reduced graphene oxide composites (rGO/AgNPs) synthesized in situ by the green reduction method, combined with the electrochemical polymerization method for preparation of molecularly imprinted polymers (MIPs) to modify the screen-printed electrodes. During the assay, the concentration of hydroxyl radicals was obtained by capturing the product 2,5-dihydroxybenzoic acid (2,5-DHBA). Under the optimal experimental conditions, the oxidation peak currents of the target 2,5-DHBA by differential pulse voltammetry (DPV) and its concentration showed a good linear relationship in the concentration ranges of 0.1 ∼ 0.5 μM and 1 ∼ 100 μM, with the limit of detection (LOD) of 0.021 μM. Interference experiments and other studies were also carried out, and the results showed that the sensor has good reproducibility, stability, and selectivity, and the comparison of the detection results with the conventional detection method, high-performance liquid chromatography, indicated the accuracy of the sensor detection, which is a convenient, sensitive, and efficient method for the detection of hydroxyl radicals.