Imprinted polymers (IPs) are cost-effective and stable synthetic affinity reagents, surpassing their natural counterparts (e.g. enzymes, antibodies, etc.). In sensing applications, IP synthesis involves coating a thin film onto transducers, e.g., electrodes in electrochemical sensors, using techniques like bulk, suspension, and precipitation polymerization. Uniformly heating the entire prepolymer solution (e.g., in an oven) in such methods lacks spatial control, leading to undesired polymerization away from the transducer and compromising coating thickness and uniformity. Removing undesired polymers, especially for IPs forming glass-like structures (instead of powders), presents challenges. Electrochemical polymerization offers spatial control via voltage applied solely at the transducer. However, it requires specialized equipment and expertise, limiting monomer and cross-linker selection due to compatibility requirements aimed at preventing degradation or electrode fouling.

I hypothesized that applying a DC current to microwires (MWs) in a prepolymer solution would create localized Joule heating, controlling polymerization and coating thickness while preventing undesired coating away from the MWs.

In this project,  we demonstrated the application of this novel electrothermal coating technique, for Salmonella bacteria imprinting on gold MWs and capturing them from water. This is the first demonstration of this electrothermal technique for coating bacteria cell imprinted polymers (CIPs) on gold transducers, presented in MicroTAS 2024 conference.