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

Abstract

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 × 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 µA cm⁻² mM⁻¹ and a LOD of 0.006 µM. The composite can be used as a flexible skin patch sensor to predict abnormal dopamine levels such as Parkinson's disease.