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

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 x 10(-8) to 4.98 x 10(-2) M and limit of detection (LOD) was 2.07 x 10(-8) M (S/N = 3). The linear range of detecting UA was from 1.25 x 10(-7) to 8.28 x 10(-2) M and LOD was 4.07 x 10(-8) M (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. (C) 2015 Elsevier By. All rights reserved.