An integrated wearable photo-electrochemical sensor for visible light amplified uric acid monitoring in sweat.

Uric acid (UA), a crucial biomarker for chronic metabolic disorders such as gout and hyperuricemia, necessitates non-invasive monitoring for effective disease management. However, wearable sensor for real-time UA detection face significant challenges due to the low UA concentration (<100 μM) in human sweat and the difficulty of multi-functional integration. Here, we developed an integrated wearable photo-electrochemical (PEC) sensor for UA detection in sweat. The sensor comprises iontophoresis electrodes, micro-channel, PEC detection unit and signal system, successfully integrating the functions including the sweat induction, sample collection, visible light amplified UA detection, as well as signal processing and wireless communication. With the ion-doping and Z-scheme heterojunction effect, the In doped ZnS/reduced graphene oxide/BiVO4 (ZIS/RGO/BVO) modified enzymatic working electrode facilitates the photo-generation and separation of the electron and holes, leading to an excellent PEC response under the visible light irradiation. The resultant sensor demonstrates exceptional performances with a sensitivity 280 μA mM-1·cm-2, a limit of detection (LOD) 0.23 μM (S/N = 3), and a broad linear range from 10 to 450 μM respectively. This integrated wearable sensor establishes a paradigm for sweat-based metabolic monitoring, showing remarkable potential for the personalized diagnosis of gout and hyperuricemia.