Label-free monitoring of the thrombin-aptamer recognition reaction using an array of nanochannels coupled with electrochemical detection

- A bioanalysis device based on a nanochannel array was developed.
- Efficient thrombin-aptamer recognition occurs in the nanochannels of porous anodic alumina.
- This device can be used to detect biomolecular recognition reactions when integrated with an electrochemical detector.
- The method has potential applications in biological analysis and clinical diagnosis.

A sensitive and label-free method of monitoring the thrombin-aptamer recognition reaction has been developed using an array of nanochannels coupled with an electrochemical detection technique. Due to the highly amplified ion current produced by an array of nanochannels compared to a single nanochannel/pore, a significant increase in detection sensitivity has been achieved.

A sensitive and label free assay of thrombin-aptamer recognition reaction has been performed using array nanochannels coupled with electrochemical detection technique. Thrombin aptamer (TBA) is immobilized in the array nanochannels through chemical coupling. In the presence of thrombin, the molecules recognition between thrombin and TBA occurs, which induces the change of TBA conformation from a soft single strand structure to tightly patterned G-quadruplex, resulting in a decreased free space for ions transport in array nanochannels. When a potential is applied, the current-voltage (I-V) curve of the array nanochannels is detected by a home-made electrochemical cell. Consequently, the I-V properties of the array nanochannels changes accordingly. From this change, a label-free assay of thrombin-TBA recognition can be achieved in real-time. Due to the highly amplified ion current magnitude of array nanochannels compared to single nanochannel/pore, significantly increased assay sensitivity can be achieved.147