Electrochemical Detection of 1,3-Dinitrobenzene Using Bimetallic CoAg/rGO and CuAg/rGO Nanocomposites

This study introduces an electrochemical sensing platform based on bimetallic CoAg/rGO and CuAg/rGO nanocomposites for the detection of 1,3-dinitrobenzene (DNB), a highly toxic nitroaromatic compound commonly encountered in industrial effluents and contaminated water systems. The prepared nanocomposites were characterized using SEM, TEM, AFM, XPS, and electrochemical techniques, providing detailed insight into their structural, morphological, and surface properties relevant to electrochemical sensing. The electrochemical behavior of DNB was investigated in phosphate buffer solutions using cyclic voltammetry under optimized experimental conditions. Both CoAg/rGO and CuAg/rGO electrodes exhibited pronounced electrocatalytic activity towards the reduction in DNB, characterized by well-defined reduction peaks. The developed sensors exhibited good analytical performance, with limits of detection of 2.21 µM and 2.47 µM for the CuAg/rGO and CoAg/rGO electrodes, respectively, both showing linear responses in the concentration range of 5–50 µM. Moreover, a clear response to DNB was obtained in the presence of phenols as interferents as well as in spiked real water samples. The integration of characterization results with electrochemical measurements and validation in real water samples supports process-oriented research in environmental monitoring and electrochemical process control. These results confirm that bimetallic rGO-based nanocomposites represent efficient and cost-effective electrode materials for the electrochemical detection of 1,3-dinitrobenzene.