Self-Powered Enzyme-Functionalized Active Sensing System for Real-Time Noninvasive Sweat Biomarker Monitoring

Abstract

To address the limitations of external power reliance in wearable health monitoring, this study presents an integrated microfluidic, self-powered sweat sensing, and communication system (IMSSC) for the real-time detection of critical biomarkers, specifically glucose, lactic acid, and creatinine in human sweat. Leveraging the triboelectric nanogenerator (TENG) technology, the system converts human motion-induced mechanical deformation into electrical signals, obviating the need for an external power source. The self-powered enzyme-functionalized triboelectric sweat sensor array (SETSA) is modified with glucose oxidase (GOx), lactic acid oxidase (LOx), and creatinine amidohydrolase (CA), which catalyze specific enzymatic reactions to generate an electrical current proportional to the analyte concentrations. A multichannel microfluidic module ensures uniform and stable sweat delivery, thereby minimizing measurement fluctuations. Furthermore, the IMSSC includes an nRF52840 Bluetooth communication module that enables seamless wireless transmission of real-time data to smartphones. Experimental results demonstrate that the SETSA exhibits superior analytical performance, including high sensitivity (<inline-formula> <tex-math notation="LaTeX">$1.2~\mathrm {nA{\,}L{\,}\mu mol^{-1}}$ </tex-math></inline-formula>), a strong linear correlation between output current and analyte concentration (R<inline-formula> <tex-math notation="LaTeX">${}^{{2}} {\,}={\,}~0.98$ </tex-math></inline-formula>), and a low detection limit of <inline-formula> <tex-math notation="LaTeX">$1~\mathrm {\mu mol{\,}L^{-1}}$ </tex-math></inline-formula>. This synergistic combination of self-powered active sensing, high specificity, and real-time wireless data transmission offers a promising strategy for noninvasive biomarker monitoring and establishes a foundation for next-generation intelligent wearable biosensing systems.