▎ 摘　　要

Herein, graphene was proposed as a simple label-free electrochemical sensing platform. In this sensing strategy, the graphene modified electrode was used to bind aptamer by physical adsorption. The aptamer on the graphene surface could catch the target protein in the solution, which made a neutralization of the negatively charged phosphate backbone of the aptamer, resulting in the decrease of the electrochemical signals of surface-bound [Ru(NH3)(6)](3+). This strategy could be applied in logic aptasensor. Through the built-in NAND logic gate, it enabled us to construct logic aptasensor that could determine whether the two specific targets at saturated concentrations were both present in a sample. (C) 2012 Elsevier B.V. All rights reserved.