Electrochemical sensing of dopamine, uric acid, and paracetamol using a quinoline-azo dye modified carbon paste electrode

In this study, a novel azo dye, 5-(Z)-1,3-thiazol-2-yldiazenylquinolin-8-ol (TDQ), was synthesized and used as modifier for carbon paste electrode (CPE). TDQ modified CPE employed for the selective electrochemical detection of dopamine (DA), uric acid (UA) and paracetamol (PA) using cyclic voltammetry (CV). The TDQ was characterized by ATR-IR spectroscopy, UV-Visible, 1H-NMR, mass and elemental analysis. The TDQ/MCPE demonstrated good electrocatalytic activity for the oxidation of DA with high selectivity in the presence of UA and PA. The sensor exhibited a linear response for DA, UA and PA detection with a LOD of 6.86 µM, 10.28 µM, and 15.93 µM. LOQ of DA 21.150 µM, UA is 34.29 µM, and PA is 42.58 µM. additionally, the modified electrode showed a relative standard deviation (RSD %) of 0.85% demonstrating good stability and reproducibility.