Nanochannel-Ionchannel Hybrid Device for Ultrasensitive Monitoring of Biomolecular Recognition Events

We propose an in-situ and label-free method for detection of biomolecular recognition event using nanochannel-ionchannel hybrid device integrated with an electrochemical detector. The aptamer is first immobilized on the outer surface of the nanochannel-ionchannel hybrid. Its binding with target thrombin in solution considerably regulates the mass transfer behavior of the device owing to the varied surface charge density and effective channel size. Using the electrochemical detector, the changed mass transport property can be in real-time monitored, which enables in-situ and label-free detection of thrombin-aptamer recognition. The solution pH has a significant influence on the detection sensitivity. Under optimal pH condition, the detection limit as low as 0.22 fM thrombin can be achieved, which is much lower than most reported work. The present nanofluidic device provides a simple, ultrasensitive and label-free platform for monitoring the biomolecular recognition events, which would hold great potential ...