Extending Electrochemical Aptamer-Based Sensing to Microfabricated Sensor Formats

Electrochemical aptamer-based (EAB) sensing is a generalizable approach to monitoring a wide range of molecular targets. Selective, dynamically responsive, real-time measurements are possible in complex body fluids while using standard electrochemical methods for read out. To advance miniaturized, wearable EAB sensing formats, 17 candidate materials compatible with microfabrication into 2D and 3D microstructures were investigated as sensor substrates. Since the aptamer attachment chemistry requires a gold surface, adhesion of gold thin films was evaluated followed by compatibility with EAB surface functionalization chemistry and the electrochemical interrogation method. Sensing results for each material were benchmarked against the gold standard solid gold microwire sensor format. Finally, two microneedle-based EAB sensor formats were demonstrated at the benchtop andin vivo, by modifying commercially produced microneedles and developing a novel laser-machined polyether ether ketone (PEEK) microneedle array. Multiplexed sensing was enabled by selective functionalization of subgroups of needles within a single array.[2025-0204]