Glucose-to-Resistor Transduction Integrated into a Radio-Frequency Antenna for Chip-less and Battery-less Wireless Sensing

To maximize the potential of 5G infrastructure in healthcare, simple integration of biosensors with wireless tag antennas would be beneficial. This work introduces novel glucose-to-resistor transduction, which enables simple, wireless biosensor design. The biosensor was realized on a near-field communication tagantenna, where a sensing bioanode generated electrical current and electroreduced a nonconducting antennamaterial into an excellent conductor. For this, a part of the antenna was replaced by a Ag nanoparticle layeroxidized to high-resistance AgCl. The bioanode was based on Au nanoparticle-wired glucose dehydrogenase(GDH). The exposure of the cathode-bioanode to glucose solution resulted in GDH-catalyzed oxidation ofglucose at the bioanode with a concomitant reduction of AgCl to highly conducting Ag on the cathode. TheAgCl-to-Ag conversion strongly affected the impedance of the antenna circuit, allowing wireless detection ofglucose. Mimicking thefinal application, the proposed wireless biosensor was ultimately evaluated through themeasurement of glucose in whole blood, showing good agreement with the values obtained with acommercially available glucometer. This work, for thefirst time, demonstrates that making a part of the antenna from the AgCl layer allows achieving simple, chip-less, and battery-less wireless sensing of enzyme-catalyzed reduction reaction