Gold nanoparticle-decorated MoS2 nanosheets for simultaneous detection of ascorbic acid, dopamine and uric acid

An electrochemical sensor has been developed for simultaneous detection of dopamine (DA), uric acid (UA) and ascorbic acid (AA) based on a gold nanoparticle-decorated MoS2 nanocomposite (AuNPs@MoS2) modified electrode. The AuNPs@MoS2 nanocomposite has been synthesized by electrodeposition of AuNPs on the MoS2 nanosheets, which possesses better properties than pure AuNPs and MoS2. The AuNPs@MoS2 film modified electrode showed excellent electrocatalytic activity toward the oxidation of AA, DA and UA with three well-resolved oxidation peaks. The peak separation of AA-DA, DA-UA and AA-UA is 151 mV, 137 mV and 288 mV, respectively, which permits the modified electrode to individually or simultaneously analyze AA, DA and UA by differential pulse voltammetry (DPV). Under optimum conditions, the AuNPs@MoS2 modified electrode exhibits linear response toward AA, DA and UA in the range of 50-100 000 mu M, 0.05-30 mu M and 50-40 000 mu M, respectively. Moreover, the MoS2-based modified electrode was successfully employed to determine DA in human serum samples with satisfactory results.