Efficient Ti ₃ C ₂ T <i> _x </i> @TiO ₂ ‐MoS ₂ Heterojunction as an Electrocatalyst for Complete Uric Acid Electrooxidation: Sensing, Mechanism and Products

Abstract Wearable and noninvasive biosensing technologies facilitate the continuous assessment of metabolites and nutrients present in sweat, offering valuable early warnings into an individual's health. Uric acid (UA) is the final product of purine metabolism in humans. Persistent elevated levels (hyperuricemia) can damage multiple body systems. Herein, a strategy for a wearable electrochemical biosensor is provided for the continuous monitoring of trace levels of disease factors and essential amino acids in sweat, including UA and tyrosine (Tyr). A heterojunction catalyst with high catalytic activity (noted as Ti 3 C 2 T x @TiO 2 ‐MoS 2 ) is developed for the sensitive and selective detection of UA and Tyr, leveraging the high electrical conductivity and facile surface regulation of Ti 3 C 2 T x MXene. The synergistic interaction between TiO 2 and MoS 2 promotes the dual‐site adsorption of UA and Tyr molecules, intensifies heterogeneous electron transfer mechanisms, and reduces the Gibbs free energy of the reaction. The integrated biosensor consists of a Ti 3 C 2 T x @TiO 2 ‐MoS 2 ‐modified screen‐printed chip, microfluidic sweat collection, and wireless electronic modules to facilitate continuous monitoring of UA and Tyr levels during physical exercise. This work provides a novel in vitro strategy for monitoring metabolites and nutrients, which can help identify abnormal health conditions at an early stage and promote the application of precision health management.