Materials Characterization for Microneedle-Based Molecular Sensing Platform

Adaptation of electrochemical aptamer-based (EAB) sensing to a microneedle format would enable clinically actionable, real-time molecular measurements via an easily applied, minimally-invasive, painless, wearable device. As a prerequisite, here we have explored what substrate materials meet the combined requirements of both microneedles and EAB sensor fabrication. Specifically, we evaluated 17 microneedle-compatible materials for adhesion with gold, the surface required for EAB functionalization. Those exhibiting satisfactory adhesion were functionalized with an aptamer sensitive to vancomycin, challenged with a range of target concentrations, and compared. Finally, we realized a microneedle sensing patch and demonstrated its function in solution and ex vivo.