Polydopamine supported gold nanoclusters for sensitive and simultaneous detection of dopamine in the presence of excess ascorbic acid and uric acid

Abstract

In this work, an adhesive layer of polydopamine (PDA) coating was synthesized by a simple electrochemical cyclic voltammetry (CV) method under optimized conditions. Then, PDA coating was used as an active support for the continuous growth of Au nanoclusters (Au NCs), by CV method using optimized growth parameters. As−prepared, Au NCs deposited PDA (Au NCs@PDA) thin film was considered as electro active probe for the electrochemical determination of dopamine (DA), ascorbic acid (AA) and uric acid (UA) simultaneously. All the electrochemical measurements were carried out by CV, differential pulse voltammetry (DPV) and amperometric techniques. The morphology of PDA coating before and after Au NCs depositions were characterized by SEM, while the deposition of Au NCs was confirmed with XPS. The thickness of PDA film before and after deposition of Au NCs was discussed by using UV−vis. absorption spectra. The sensitivity and selectivity of Au NCs@PDA electrode for DA was investigated in presence of excess AA and UA. The experimental results suggest that the Au NCs@PDA electrode can be used for real biological sample to determine DA, AA and UA simultaneously.