A Promising Electrochemical Sensor Platform for the Detection of Dopamine Using CuO-NiO/rGO Composite

Dopamine plays a significant role in the proper functioning of the central nervous system. Hence, the ability to sense levels of dopamine is pivotal in diagnosis and treatment procedures. For sensing dopamine, a mixed metal oxide nanocomposite (NC) of copper oxide-nickel oxide/reduced graphene oxide (CuO-NiO/rGO) is fabricated by the sol-gel method, and it is used to modify the glassy carbon electrode. The structural and morphological characterizations are done by X-ray diffraction (XRD), Energy dispersive X-ray (EDAX), Raman, and Scanning electron microscopy (SEM). XRD results exhibit monoclinic CuO, cubic NiO, and hexagonal rGO structures. The Raman studies confirm the D and G bands for rGO. Different electrochemical techniques are used to examine the efficacy of nanocomposite in detecting dopamine. The CuO-NiO metal oxide NC response compared with the CuO-NiO/rGO NC shows a better response by rGO containing nanocomposite.Further, the chronoamperometric method is employed, and the diffusion coefficient is calculated as 1.04 x 10-6 cm2 s-1. The differential pulse voltammetry is carried out to measure the nanocomposite's sensitivity and detection limit (LOD). The catalyst exhibits a sensitivity of 7.2 mu A cm-2 mM-1 and a LOD of 0.006 mu M. The composite can be used as a flexible skin patch sensor to predict abnormal dopamine levels such as Parkinson's disease.