Development of an efficient electrochemical sensor based on CuAl-LDH for the selective determination of dopamine in the presence of uric acid and ascorbic acid species

Dopamine (DA) is a catecholamine neurotransmitter that plays a crucial role in the proper operation of mammals central nervous systems. DA levels play a significant role in regulating the functions of the body. Therefore, it is essential to design a rapid and sensitive electrochemical sensor for the detection of DA [1, 2]. This paper presents a novel, environmentally friendly electrochemical sensor that has high sensitivity and selectivity. The CuAl-LDH/GCE as the suggested sensor has been synthesized using an easy one-step co-precipitation procedure [3], and the first time was utilized to determine dopamine with differential pulse voltammetry. At optimal pH (pH=8), dopamine is positively charged, while ascorbic acid and uric acid are negatively charged, and LDH is negatively charged and is strongly electrostatically attracted to dopamine but electrostatically repelled by negatively charged ascorbic acid and uric acid. Therefore, CuAl-LDH/GCE offers the possibility to selectively determine dopamine in the presence of these species. The composition and morphology of CuAl-LDH was examined by scanner electron microscopy (FESEM), transmission electron microscope (TEM), element mapping (MAP), Fourier transform infrared (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron diffraction (XRD), and Raman techniques. In optimal conditions, the dopamine calibration graph was plotted by differential pulse voltammetry. The linear range of 4.194–1151.54 μM was obtained with limit of detection of 0.33 μM for dopamine. The results demonstrate the great stability, repeatability, and reproducibility of the developed sensor for dopamine determination. The proposed sensor was satisfactorily used to measure dopamine in pharmaceutical ampoule and human plasma samples.