Synergistic Redox Activity in Transition Metal-Manganese Oxide Nanohybrids for Morphine Electro-Analysis

Abstract Despite its effectiveness in reducing pain, the widespread use of morphine for self-medication and its illicit sale pose a significant threat to society, necessitating the development of a sensitive and selective detection technology. In this work, morphology-controlled MnO2 using different oxidizing agents was prepared, and the best one was loaded with nickel, copper, and gold individually and studied using XRD, TEM, HR-TEM, IR, Raman, and XPS. Their performance in terms of morphine sensing was evaluated using CV, DPV, and EIS. The experimental result is well validated by the theoretical calculations using DFT. According to the DFT calculation, morphine’s superior adsorption capacity, improved electronic coupling, and interfacial charge redistribution are responsible for Ni/MnO2 superior performance. With an LOD of 0.0429 μM and LOQ of 0.143 μm, the sensitivity of Ni/MnO2 was found to be significantly higher than its counterparts.