▎ 摘　　要

A label-free and ultrasensitive electrochemiluminescence (ECL) aptasensor was constructed for the detection of thrombin. Molybdenum sulfide-graphene nanocomposites with good conductivity and large surface area were immobilized on glassy carbon electrode (GCE), and then Nafion was fixed to chemosorb the Ru(bpy)(3)(2+) used as luminescence agent. Subsequently, gold nanoparticles (AuNPs) were modified on the electrode to immobilize the thiol-modified thrombin aptamer for fabrication of the thrombin aptasensor. The proposed ECL aptasensor produced the ultrasensitive detection of thrombin with a low detection limit of 3.6 x 10(-15) M (S/N = 3) and over a wide target concentration range from 1.0 x 10(-14) to 5.0 x 10(-9) M. The aptasensor has been successfully applied in the determination of thrombin in human plasma samples of both traumatic and non-traumatic injury patients, indicating its promise in biochemical analysis. The recoveries of thrombin in human plasma samples are between 88.6% and 105.0%, and the RSD values are no more than 3.7%. The results demonstrate that this aptasensor has excellent sensitivity, selectivity and stability. (C) 2014 Elsevier B.V. All rights reserved.