Aptamer serves as a potential candidate for the micro-detection of cocaine due to its high specificity,high affinity and good stability.Although cocaine aptasensors have been extensively studied,the binding mechanism ...Aptamer serves as a potential candidate for the micro-detection of cocaine due to its high specificity,high affinity and good stability.Although cocaine aptasensors have been extensively studied,the binding mechanism of cocaine-aptamer interactions is still unknown,which limits the structural refinement in the design of an aptamer to improve the performance of cocaine aptasensors.Herein,we report a label-free,ultrasensitive detection of single-molecule cocaine-aptamer interaction by using an electrical nanocircuit based on graphene-moleculegraphene single-molecule junctions (GMG-SMJs).Real-time recordings of cocaine-aptamer interactions have exhibited distinct current oscillations before and after cocaine treatment,revealing the dynamic mechanism of the conformational changes of aptamer upon binding with cocaine.Further concentration-dependent experiments have proved that these devices can act as a single-molecule biosensor with at least a limit of detection as low as 1 nmol·L^-1.The method demonstrated in this work provides a novel strategy for shedding light on the interaction mechanism of biomolecules as well as constructing new types of aptasensors toward practical applications.展开更多
基金The authors ack no wledge primary fin ancial support from the National Key R&D Program of China (No. 2017YFA0204901)the National Natural Science Foundation of China (No. 21727806)the Natural Science Foundation of Beijing (No. Z181100004418003) and the Interdisciplinary Medicine Seed Fund of Peking University.
文摘Aptamer serves as a potential candidate for the micro-detection of cocaine due to its high specificity,high affinity and good stability.Although cocaine aptasensors have been extensively studied,the binding mechanism of cocaine-aptamer interactions is still unknown,which limits the structural refinement in the design of an aptamer to improve the performance of cocaine aptasensors.Herein,we report a label-free,ultrasensitive detection of single-molecule cocaine-aptamer interaction by using an electrical nanocircuit based on graphene-moleculegraphene single-molecule junctions (GMG-SMJs).Real-time recordings of cocaine-aptamer interactions have exhibited distinct current oscillations before and after cocaine treatment,revealing the dynamic mechanism of the conformational changes of aptamer upon binding with cocaine.Further concentration-dependent experiments have proved that these devices can act as a single-molecule biosensor with at least a limit of detection as low as 1 nmol·L^-1.The method demonstrated in this work provides a novel strategy for shedding light on the interaction mechanism of biomolecules as well as constructing new types of aptasensors toward practical applications.
