Abstract

Molecular-Imprinted Thrombin Responsive Hydrogel-Integrated into a Microfluidic Device with Electronic Readout

Hsuan-Yu Leu, Graduate Student, University of Utah

There is a significant need for new point-of-use sensors for biomedical applications. For example, thrombin, an FDA approved protein utilizing in surgery for hemostatic, is detected using clotting-based assays, enzymatic activity-based assays, and immunoassays. However, most of the assays need further specialized equipment for the readout. In this work, we present a low-cost microfluidics device that utilizes molecular-imprinted thrombin responsive hydrogels (MIP-TRHs) to rapidly measure thrombin concentrations in small aqueous samples. Devices were fabricated using a polycarbonate cover-sheet, double-sided adhesive vinyl with microchannels, and a glass coverslip. Approximately 50% of the microchannel was occupied by MIP-TRHs formed by in-situ polymerization. The percentage of the microchannel occupied by the MIP-TRHs decreases when the surrounding thrombin concentration increases The device utilizes an electronic readout to determine if the hydrogel shrinks in response to a stimuli. The MIP hydrogel is located in a central channel with no bound analyte. Electrodes are placed at the ends of the microchannel to measure the current through the channel. Once the analyte reaches the MIP hydrogel, the hydrogel shrinks, thereby increasing the resistance to current flow in the microchannel. The resulting electronic read-out is a change in current. We call this method resistive channel sensing.