A PVA-pCD2:1 hydrogel-based wearable patch for dual-mode sweat cholesterol and strain monitoring

A covalently crosslinked PVA-pCD 2:1 interpenetrating hydrogel network is developed. • The PVA-pCD 2:1 hydrogel enables non‑enzymatic, highly selective sweat cholesterol detection. • The PVA-pCD 2:1 hydrogel exhibits stable strain-sensing performance. • A wireless dual-mode sensing device integrated with smartphone readout is developed for personalized health management. The increasing prevalence of chronic metabolic diseases has highlighted the demand for non-invasive and convenient cholesterol monitoring technologies. However, conventional detection methods are limited by bulky instruments and poor enzyme stability, hindering their application in daily monitoring. This study presents a novel multifunctional hydrogel based on a covalently crosslinked polyvinyl alcohol-polycyclodextrin 2:1 (PVA-pCD 2:1 ) network, which combines excellent mechanical sensing performance with non-enzymatic electrochemical detection of sweat cholesterol. The citrate-crosslinked interpenetrating network endows the hydrogel with desirable mechanical properties (tensile strength: 1.2 MPa), while the excellent strain-responsive behavior ( GF  = 4.35) enables motion monitoring. More importantly, the hydrogel achieves highly selective and sensitive cholesterol detection in sweat, with a sensitivity of 0.15 μA·μM −1 ·cm −2 , a linear range of 0–100 μM, and a detection limit of 0.296 μM. A wearable sensor based on this hydrogel is developed, which integrates simultaneous monitoring of sweat biomarkers and mechanical signals. Data are wirelessly transmitted to a smartphone featuring dual modules for cholesterol and mechanical sensing, providing an innovative platform for personalized health management.