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

Abstract

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 μM, 0.05–30 μM and 50–40 000 μM, respectively. Moreover, the MoS₂-based modified electrode was successfully employed to determine DA in human serum samples with satisfactory results.