An aptamer–SWNT biosensor for sensitive detection of protein via mediated signal transduction

An aptamer–SWNT based electrochemical biosensor is developed for sensitive detection of thrombin via mediated signal transduction. To realize this purpose, a dense monolayer of 16-mercaptohexadecanoic acid was modified on the gold electrode. In the presence of thrombin, SWNTs were controllably assembled on this insulating monolayer, which could mediate efficient electron transfer between the electrode and eletroactive species to generate a larger redox current. Through detecting the redox signal mediated by SWNTs, this strategy could present significant signal amplification and a detection limit of 50 pM thrombin was achieved. Such an aptamer–SWNT based biosensor opens a rapid, selective and sensitive route for thrombin detection and offers a promising strategy for specific protein detection.

► An aptamer-SWNT based biosensor via controlled mediated signal transduction
► New bio-assay for sensitive detection of thrombin
► Detection limit of 50 pM with desirable specificity and sensitivity