Non-Enzyme, Temperature Calibrating, and Bioactive Fiber-based Flexible Sensors for Dopamine and Lactic Acid Detection

Flexible electrochemical biosensors enable the in-situ monitoring and quantification of human biochemical constituents in molecular scale, spearheading and thriving the field toward precision medicine. However, specific biorecognition elements for multiplexed biomarkers detection, temperature stability and versatility need to be improved for higher adaption. Here, we propose a bioactive sensor patch comprising a non-enzyme Co₃O₄/carbon fiber-based biorecognition element and a temperature calibration unit. The optimized serpentine configuration renders the sensor intimate and seamless attachment with skin, operating robustly even subjected to 40% tensile strain. The fiber-based sensor could selectively monitor dopamine and lactic acid contents based on cyclic voltammetry and amperometry, respectively. The bioanalytical results at room temperature indicate that the electrochemical biosensor has a wide detection range (0.001–1.100 mM for dopamine and 2–35 mM for lactic acid), excellent selectivity and reproducibility (maximum error 3.2% for dopamine and 5.6% for lactic acid). In addition, temperature calibration contour maps of these two biomarkers are established in an ambient temperature range from 25 to 45 ℃. The continuously collected data could be aggregated and wirelessly transmitted to portable devices using an electrochemical signal transducer and an acquisition module, promising personalized and preventative health care in various scenarios.