Fabrication of Au Nanoparticle-Decorated MoS₂ Nanoslices as Efficient Electrocatalysts for Electrochemical Detection of Dopamine

Herein, MoS₂ nanoslices were simply prepared by using ultrasonic treatment, and were further decorated with Au nanoparticles (AuNPs) through an electrodeposition process to obtain the MoS₂/Au nanocomposites. The obtained nanocomposites display synergetic electrocatalytic effect for the oxidation of dopamine due to the large surface area and two-dimensional structure of the MoS₂ nanoslices, combining with the high catalytic activity and good conductivity of AuNPs. An electrochemical sensor was constructed based on MoS₂/Au-modified carbon paste electrode, for sensitive and quantitative determination of dopamine. The prepared electrochemical sensor proves excellent analytical performances: very high sensitivity, wide linear ranges (0.5–300 μM), and low detection limit (76 nM). Moreover, the dopamine sensor also displays high selectivity, good reproducibility and stability, and can be used in real sample analysis. The method of fabricating high-efficiency electrocatalysts and electrochemical sensors proposed in this study provides a good reference for developing more functionalized nanocomposites and for extending practical applications.