Redox-Active Molecularly Imprinted Polymers for Electrochemical Sensor-Based Health Monitoring: Moving Closer to Real-Time Measurements

Molecularly imprinted polymers (MIPs) are robust synthetic recognition elements for electrochemical health monitoring, offering chemical stability, tunable selectivity, and compatibility with miniaturized devices. Conventional MIP sensors, however, often rely on external redox probes or the intrinsic electroactivity of the target. This dependence can add assay steps, make signals sensitive to probe diffusion, and restrict the detection of non-electroactive analytes, complicating rapid or continuous measurement in complex biological samples. Redox-active MIPs offer an alternative by integrating molecular recognition and electrochemical signal generation within the sensing interface. This review examines how redox components are incorporated into MIP architecture and how target binding modulates their electrochemical responses. It covers systems incorporating Prussian blue and related hexacyanoferrates, methylene blue and other redox-active polymers, ferrocene, copper-containing materials, metal nanoparticles, and redox-active metal oxides, with applications to biomarkers, metabolites, hormones, therapeutic agents, and other health-relevant analytes. Particular attention is given to the coupling between recognition and redox transduction, highlighting how redox-component positioning, binding-site accessibility, and interfacial electron transfer influence signal generation, as well as mass transport, electrocatalysis, regeneration, and selectivity in complex biological matrices. Remaining challenges include maintaining binding-site accessibility and efficient electron transfer, controlling redox-component placement, improving matrix tolerance and long-term stability, and adapting these interfaces for wearable and point-of-care devices. Future progress will require application-oriented evaluation of analytical performance, selectivity, measurement time, and reusability, alongside the integration of recognition chemistry, redox mechanisms, biofluid handling, and device design to support reliable, continuous, and decentralized health monitoring, including rapid measurements and, where demonstrated, continuous and decentralized monitoring.