A Flexible Copper-Doped Laser-Induced Graphene-Based Sensor for the Multiplexed Detection of Sweat Metabolites

Despite advances in wearable sweat sensors, the simultaneous detection of multiple analytes remains a challenge due to signal overlap. Ascorbic acid (AA), dopamine (DA), and uric acid (UA) are promising biomarkers for early diagnostics, but their similar oxidation potentials impede selective detection on conventional electrodes. To overcome this limitation, we developed a flexible sensor based on a copper-doped laser-induced graphene (Cu-LIG) electrode for the separate and simultaneous detection of these three biomarkers. The Cu-LIG electrode exhibits enhanced electrocatalytic activity compared to pristine LIG and performs effectively in artificial sweat. Cyclic voltammetry and differential pulse voltammetry confirm its improved electrochemical performance, including high sensitivity and low detection limits. This electrode demonstrates strong potential for integration into flexible, wearable health-monitoring devices.