Selective determination of dopamine and uric acid using electrochemical sensor based on poly(alizarin yellow R) film-modified electrode

Abstract

A sensitive and selective method based on a poly(alizarin yellow R)-modified carbon paste electrode (PAYR/CPE) to detect dopamine (DA) and uric acid (UA) was successfully established. The morphology of the electrode surface was observed by scanning electron microscopy (SEM). Electrochemical characterization of the PAYR/CPE was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was illustrated that the PAYR/CPE had excellent electro-catalytic ability toward the oxidation of DA. The anodic peak current of DA was greatly enhanced at the PAYR/CPE, and the standard rate constant (k_s) was calculated to be 6.17 s⁻¹. The linear calibration curves were obtained as 0.49–70.1 μM and 83.6–488.1 μM for DA and 27.8–304.4 μM and 381.6–1118 μM for UA by DPV. The detection limits were 0.16 μM for DA and 9.5 μM for UA. Moreover, the modified electrode was applied to the selective detection of DA and UA with high sensitivity and selectivity. Furthermore, the modified electrode displayed high reproducibility and stability for determination of these species. Thus, the proposed electrode could be conveniently employed for the determination of DA and UA in real samples and provide satisfactory results.