Efficient Fabrication of Ni6MnO8 Nanoparticles on Glassy Carbon Electrode for Simultaneous Electrochemical Sensing of Dopamine and Serotonin

A modified glassy carbon electrode (GCE) with immobilized nickel manganese oxide nanoparticles (Ni6MnO8 NPs) was developed for the sensitive and selective detection of dopamine (DA) in the presence of serotonin (5-HT). The Ni6MnO8 NPs were synthesized and characterized by using techniques such as powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), elemental mapping, energy dispersive X-ray analysis (EDAX), and High-resolution transmission electron microscopy (HR-TEM). Electrochemical studies of the Ni6MnO8 NPs for detecting DA and 5-HT were conducted using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimal conditions, DPV was used for the simultaneous detection of DA and 5-HT at Ni6MnO8 NPs modified surfaces, achieving low detection limits of 0.021 µM for DA and 0.11 µM for 5-HT. The fabricated sensor demonstrated excellent reproducibility and stability, making it suitable for the analysis DA and 5-HT simultaneously. Additionally, the sensor showed satisfactory recovery rates in real sample analyses.