▎ 摘　　要

In this paper, PtPd alloy decorated reduced graphene oxide (RGO/PtPd) was synthesized by a simple and green method. The RGO/PtPd could catalytic oxidation of H2O2 to form O-2 and O-2 acted as the coreactant of peroxydisulfate, could greatly amplify the ECL signal. Moreover, the RGO/PtPd exhibited higher catalytic activity compared to the RGO/Pt or RGO/Pd catalyst because of the synergetic effects of Pt and Pd and the enhanced electron transfer of RGO. Based on this, a highly sensitive and selective label-free electrochemiluminescence (ECL) aptasensor for detection of adenosine triphosphate was designed. In this process, RGO/PtPd could be regarded as mimicking enzyme, the effect of which was similar to horseradish peroxidase in generating O-2 and also used as carriers to immobilize ssDNA2. With respect to sensitivity, Ag dendrites with hierarchical nanostructures were electrodeposited on working electrode of portable indium tin oxide device, which improved the electronic transfer rate as well as increased the amount of immobilized capture ssDNA1. Under the optimal conditions, the approach provided a linear range from 0.1 pM to 50 nM and a low detection limit of 0.037 pM. (C) 2014 Elsevier B.V. All rights reserved.