Carbon-Based-Polypyrrole Composite Nanowires for Portable and Remote Trace Sweat Lactate Detection

The prompt and remote detection of biomarkers is crucial in personalized medicine and health protection, presenting a significant challenge for current devices. In this context, we introduce a highly sensitive method for remotely analyzing sweat lactate, utilizing carbon nanotube-composite polypyrene with the capability of transmitting data. The sensing mechanism is attributed to the charge transfer of polypyrene during anion doping, enabling the selective detection of lactate anions at specific potentials, while maintaining inertness to neutral and cationic substances found in human sweat. Timed-current studies revealed robust sensing properties for lactate, demonstrating a sensitivity of up to 1.8 mA·mM-1cm-2 and a detection limit of 25 μM. Additionally, CNT-polypyrene nanowires exhibited outstanding selectivity for lactate. This breakthrough overcomes the limitations of traditional electrochemical sensors, offering a direction and theoretical foundation for designing wearable sensors to address various stimulus detection needs.