Recent progress in wearable electrochemical sensors based on MXene-conductive hydrogels.

MXene-based conductive hydrogels (MCHs) have emerged as highly promising materials for next-generation wearable electrochemical sensors, owing to their exceptional electrical conductivity, mechanical flexibility, and biocompatibility. This review provides a comprehensive and up-to-date overview of recent advances in the development of wearable sensors that incorporate Ti3C2Tx MXene hydrogels for the detection of a wide range of analytes in various biofluids. Diverse hydrogel matrices have been integrated with MXenes to fabricate highly sensitive platforms capable of monitoring key biomarkers such as glucose, dopamine, uric acid, lactate, norepinephrine, sodium, creatinine, and pH. These sensors have been successfully deployed at various locations in the body, including the forearm, chest, wrist, and head, using flexible formats such as skin patches, microfluidic devices, pantyliners, wearable caps, and attachable body accessories. Notably, several configurations demonstrate ultralow detection limits, reaching the nanomolar level, enabling real-time, noninvasive analysis of sweat, urine, and other physiological fluids. The wide range of functional additives and customizable design approaches underscores the modularity and tunability of MCH-based systems for specific applications. This review critically evaluates the design principles, sensing mechanisms, performance metrics, and practical limitations of current MCH-based wearable platforms, providing insights that can guide future innovations in smart wearable healthcare technologies.