Real-time monitoring of L-dopa levels is crucial for effective Parkinson's disease management, yet current approaches lack the integration, flexibility, and self-sufficiency needed for wearable applications. Herein, we present a fully integrated, wearable, self-powered biosensor system for non-invasive L-dopa detection in sweat with high sensitivity and specificity. The device comprises three core components: a sensitive electrochemical biosensor, a high-performance flexible supercapacitor energy source, and a custom-designed electronic interface for signal processing and display. The supercapacitor consists of CuO nanowires@NiCo layered double hydroxide (CuO NWs@NiCo LDH) positive electrode paired with a thermally-reduced graphene oxide (TRGO)-coated nickel foam negative electrode. This core–shell design delivers outstanding electrochemical performance, exhibiting a specific capacitance of 94.5 F/g and excellent rate capability, enabling a significant energy density of 32 Wh/kg at 1 A/g and a power density of 7500 W/kg at 10 A/g, using only 1 mg of active materials per 1 cm2 for each electrode. The L-dopa biosensor is constructed on a flexible Au-coated Kapton substrate and is functionalized with a graphene oxide nanoribbon–poly(3,4-ethylenedioxythiophene) (GONR–PEDOT) composite via pulse potential electrodeposition, followed by coating with tyrosinase enzyme. The prepared biosensor exhibits a high sensitivity of 0.0649 μA/μM.cm2 for L-dopa in vitro, with a detection limit as low as 8 nM, and demonstrates reliable performance in detecting L-dopa concentrations in real human sweat samples. Together, these components form a compact, body-compliant system for continuous, non-invasive monitoring of L-dopa, offering significant promise for personalized disease management in Parkinson's patients.
