High-sensitivity flexible electrochemical sensor for real-time multi-analyte sweat analysis

Flexible sweat sensors play a crucial role in health monitoring and disease prevention by enabling real-time, non-invasive assessment of human physiological conditions. Sweat contains a variety of biomarkers, offering valuable insights into an individual's health status. In this study, we developed an advanced flexible electrochemical sensor featuring reduced graphene oxide (rGO)-based electrodes, modified with a composite material comprising nitrogen and sulfur co-doped holey graphene (HG) and MXene, with in-situ-grown TiO 2 nanoparticles on the MXene. The sensor design leverages the synergistic properties of its components: MXene provides a conductive scaffold, TiO 2 enhances electrocatalytic activity, and the porous HG network facilitates efficient ion and electron transfer, with doping increasing the number of active sites. This configuration enables sensitive and simultaneous detection of ascorbic acid (AA), uric acid (UA), and dopamine (DA). Additionally, a potassium-selective (K⁺) film applied to rGO-enhanced electrodes supports concurrent detection of K⁺ in sweat. The sensor array demonstrates a broad detection range, low detection limits, and high sensitivity, while maintaining mechanical flexibility, anti-interference capabilities, and repeatability. Validated through in-situ sweat biomarker detection during exercise, the sensor effectively tracked fluctuations in K⁺, AA, and UA levels in a volunteer. This practical application underscores the sensor's potential for continuous health monitoring, and early disease detection, establishing it as a promising tool in modern healthcare.