A novel sensor based on electrodeposited Au–Pt bimetallic nano-clusters decorated on graphene oxide (GO)–electrochemically reduced GO for sensitive detection of dopamine and uric acid

Abstract

Sensitive and simultaneous detection of dopamine (DA) and uric acid (UA) by a sensor based on in-situ electrodeposited Au–Pt bimetallic nano-clusters decorated on graphene oxide (GO)–electrochemically reduced GO (ERGO) modified glassy carbon electrode (GCE) was presented. The synergistic electrocatalytic effect of Au–Pt bimetallic nano-clusters and GO–REGO was investigated. First, the comparisons of electrochemical properties for GO, GO–REGO, Au (or Pt) nanoparticles, Au–Pt bimetallic nano-clusters decorated on GO–REGO were studied in detail. Second, electrochemical parameters of DA and UA were evaluated. It was observed that for the novel Au–Pt/GO–ERGO nanocomposites, GO–ERGO could provide much wider separation of the oxidation peak potentials of DA and UA, while Au–Pt bimetallic nano-clusters could speed up the electron transfer and enhance the electro-active areas. The linear range of detecting DA was from 6.82×10−8 to 4.98×10−2M and limit of detection (LOD) was 2.07×10−8M (S/N=3). The linear range of detecting UA was from 1.25×10−7 to 8.28×10−2M and LOD was 4.07×10−8M (S/N=3). The sensor was applied for the detection of DA and UA in human serum with good results. The sensor suggested that 3D metal-GO nanocomposites were superior materials for the fabrication of novel electrochemical sensors.