Electrochemical Enzyme-Free Dopamine Sensor Based on Prussian Blue Analogues Oxides and MWCNTs

Dopamine is an important catecholamine neurotransmitter and its precise determination is of great significance in the diagnosis and treatment of related diseases. This study presents a high-performance enzyme-free electrochemical sensor for dopamine determination based on the combination of Prussian blue analogues oxides with multi-walled carbon nanotubes (PBO@CNTs). The prepared PBO@CNTs exhibited an increased surface area of 49.79 m2/g with abundant mesoporous nanostructure, which providing numerous electroactive sites. Under the optimal conditions, the PBO@CNTs/Au exhibited a high sensitivity of 178.34 mu A mM-1 cm-2, a broad linear range between 0.30 mu M to 8 mM and a low detection limit of 0.10 mu M. It displayed an excellent selectivity towards dopamine by the successive addition of various interfering species through chronoamperometry studies. Besides, the proposed electrodes enjoyed the excellent repeatability, reproducibility and long-term stability. We also demonstrated the successful application of this sensor for the determination of dopamine in serum. The results indicated that the dopamine-selective electrochemical enzyme-free sensors have great potential in clinical application.