Molecularly Imprinted Electrochemical Sensor Based on Cu x O/MXene Nanocomposite for Sensing of Melatonin

A molecularly imprinted electrochemical sensor was designed for the quantitative and efficient detection of melatonin (MT) based on CuxO/Mxene modified screen-printed carbon electrode (MIP/CuxO/MXene/SPCE). The composite of CuxO/MXene were used to improve the electrochemical response of the MIP/CuxO/MXene/SPCE sensor. The MIP film was constructed by electropolymerization of o-phenylenediamine (o-PD) in the presence of MT on the surface CuxO/MXene/SPCE. The morphology and chemical composition of the hybrid film were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, the electrochemical behaviors of the sensor were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimal conditions, MIP/CuxO/MXene/SPCE sensor had a wide linear detection range of 5-700 μM and a low detection limit of 0.029 μM (S/N=3) for MT. The sensor also showed excellent selectivity, reproducibility and stability. Finally, it was successfully applied for MT detection in human urine with satisfactory recovery. Overall, this study provided a sensitive and efficient strategy for the determination of MT.