Battery-less lactate monitoring system using a non-enzymatic sensor with selectivity

Background: Point-of-care testing (POCT) offers exciting potential for delivering real-time and continuous measurements at an affordable price for a broad range of individuals. Nevertheless, continuous monitoring to proactively manage health and reduce healthcare expenses presents a set of formidable challenges. These hurdles predominantly revolve around ensuring the reliability of recognition elements and the long-term sustainability of power sources, notably batteries. Method: This study presents a robust lactate monitoring system that operates independently of batteries and remains unaffected by environmental conditions. The sensor's selectivity has been improved by electrografted ionic liquid. To enable sustained operation with minimal power consumption, a specially designed portable potentiostat has been used, allowing power to be supplied through a magnetoelectric transducer. Significant findings: We introduce a novel point-of-care testing (POCT) system featuring a non-enzymatic sensor with enhanced selectivity using an ionic liquid layer, an integrated hydrogel reference electrode, and wireless power for the portable potentiostat. These innovations improve electrochemical detection, ensuring high reproducibility and mobility while accommodating neutral pH samples. Moreover, sensors incorporating the ionic liquid layer displayed a linear detection range from 1 to 60 mM, with a sensitivity of 1.374 mu A/mM, and excellent specificity towards lactic acid. Furthermore, the magnetoelectric transducer and power management circuit demonstrated enhanced wireless power transfer, achieving a high transmitting power efficiency of 0.74 mW to operate detections with 11 min intervals. The system matches commercial instruments and operates with low power consumption, establishing a sustainable monitoring platform.