Electrochemical, aptamer-based sensors (E-ABs) achieve specific, continuous, and real-time molecular measurements in vivo. Their selectivity and modularity originate from the use of nucleic acid aptamers – DNA oligos selected in vitro for their ability to bind to specific molecular targets. To create E-ABs, redox-reporter-modified aptamers are attached to gold electrodes via self-assembly. These modified aptamers are designed to have two thermodynamic states: one unbound, slow electron transferring state in the absence of target, and one bound, fast electron transferring state in the presence of target. The two states exist in dynamic equilibrium (the aptamers reversibly bind to and dissociate from their targets at rates of milliseconds); thus, their fractional populations depend on target concentration. This sensor architecture readily allows continuous sensing in vivo via serial electrochemical interrogation. Unfortunately, however, E-AB signals degrade within hours in the complex environments found in the body. This is in part due to biofouling but also to progressive changes in the chemical interface of these sensors driven by kinetic and biological processes. In response, the Arroyo lab is investigating the different mechanisms driving E-AB signal decay in vivo. This presentation will discuss strategies we have explored to reengineer the E-AB interface to enable continuous, multiday E-AB sensing.

Engineering nuclease-resistant electrochemical, aptamer-based sensors for prolonged in-vivo deployment

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.