Graphene-interfaced stretchable sweat patch for multiplexed electrochemical monitoring of IL-6, glucose, and calcium ions

Official URL: https://dx.doi.org/10.1002/admt.70991

Wearable electrochemical sensors are rapidly advancing toward non-invasive health monitoring, but most devices remain limited to single-analyte detection or rely on rigid substrates with poor skin compatibility. Here, we report a fully integrated and flexible sweat patch featuring interdigitated graphene/gold microelectrodes and a microfluidic platform for multiplexed detection of interleukin-6 (IL-6), glucose, and calcium ions in microliter sweat volumes. Graphene nanostructures enhance charge transfer and enlarge the electroactive surface area, while biofunctionalization with antibodies, enzymes, and ion-selective membranes ensures analyte-specific recognition. The microfluidics module prevents evaporation and drives sweat through capillary forces, enabling stable signal acquisition. The device demonstrates dynamic ranges of 0.1–300 pg mL−1 for IL-6, 10 µM–1 mM for glucose, and 0.25–3 mM for Ca2+, covering physiologically relevant levels in human sweat. Linear regression yielded high correlation coefficients (R2 > 0.97) with limits of detection of 10 pg mL−1 (IL-6), 6 µM (glucose), and 26 µM (Ca2+). Compared with recently reported wearable sweat sensors, our device uniquely integrates multiplexed detection of inflammatory, metabolic, and electrolyte biomarkers on a flexible sensor platform. This work demonstrates the potential of graphene-interfaced sweat patches for real-time, personalized health monitoring and future wireless, on-body clinical translation.