An enzyme-free flexible and wearable sensor based on PEDOT/CNTs/Au for continuous detection of glucose in sweat

Non-enzymatic electrochemical glucose sensors based on human sweat offer a new detection method that is non-invasive and suitable for continuous monitoring. They overcome limitations of traditional enzyme-based sensors, such as poor stability and strict storage requirements. This study developed a flexible electrochemical sensor using a composite of conductive polymer (P(EDOT-MeOH)), carboxylated multi-walled carbon nanotubes (COOH-MWCNTs), and gold nanoparticles (AuNPs) for highly sensitive and selective detection of glucose in sweat. COOH-MWCNTs provide a conductive network with high specific surface area. AuNPs enhance the electrocatalytic oxidation of glucose. The P(EDOT-MeOH) matrix improves the stability of the nanocomposite and effectively suppresses interference from electroactive substances such as uric acid and ascorbic acid in sweat. The sensor was fabricated using an electrodeposition process to layer the composite material onto a flexible screen-printed carbon electrode. This design offers both mechanical durability and wearability. Electrochemical tests showed that the sensor has a wide linear detection range (0.01–1 mM), a low detection limit (4.5 μM), and high selectivity under neutral conditions. The sensor maintained stable performance over 30 days and after 400 bending cycles, demonstrating its potential for wearable applications. During real-time sweat glucose monitoring in exercise conditions, results showed a strong correlation with blood glucose levels (R² = 0.976), confirming clinical applicability. This study provides a new strategy for developing low-cost, highly stable flexible non-enzymatic glucose sensors and supports the advancement of a new generation of wearable health monitoring devices.