Netz Arroyo (Johns Hopkins)

"Monitoring the Movement of Molecules in the Body via Real-time Aptamer-based Sensors"

Abstract:   Electrochemical, aptamer-based sensors (E-ABs) enable specific, continuous, and real-time molecular measurements in vivo. Their selectivity and modularity stem from the use of nucleic acid aptamers—single-stranded DNA oligos selected in vitro for their ability to bind specific molecular targets. To create E-ABs, redox-reporter-modified aptamers are attached to gold electrodes via thiol-based self-assembly. These modified aptamers are engineered to exhibit two thermodynamic states: an unbound, slow electron-transferring state in the absence of the target, and a bound, fast electron-transferring state in the presence of the target. The two states exist in dynamic equilibrium, with the aptamers reversibly binding to and dissociating from their targets within milliseconds; thus, their fractional populations depend on target concentration. This sensor architecture facilitates continuous molecular sensing in vivo through serial electrochemical interrogation. Leveraging this unique capability, the Netz Lab is using E-ABs to study molecular transport across biological membranes in vivo, focusing specifically on two systems: therapeutic transport from blood to the brain, and from blood to dermal interstitial fluid. This presentation will discuss our achievements to date, as well as the many open questions that remain.

Originally published at chemistry.nd.edu.