Sensitive and selective dopamine sensor based on novel conjugated polymer decorated with gold nanoparticles

A novel surface material was fabricated for the first time at a glassy carbon electrode based on electrochemical polymerization of poly(2,4,6-triaminopyrmidine) (PTAP) decorated with gold nanoparticles (AuNPs). A schematic reaction mechanism was proposed to account for the aggregation of the polymer. The electrochemical performance and surface characterization were achieved employing cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy (XPS), atomic force microspectroscopy (AFM) and energy dispersive system (EDS). Synergistic effects of the composite hybrid of PTAP and AuNPs promote the catalytic efficiency of the developed (AuNPs-PTAP/GCE) sensor for the electrochemical detection of dopamine (DA). The sensor showed an excellent selectivity for DA quantification with a detection limit of 0.017 μM in electrolytic medium composed of large amounts of ascorbic acid (AA) and uric acid (UA). The sensor was also applied for DA detection in real samples with satisfactory coverage.