Durable, Breathable, and Flexible Sensor Based on Vapor‐Phase Polymerized PANI‐Coated PUC‐CoNi‐LDH@PANI Composite for Continuous Sweat Glucose Monitoring

The increasing prevalence of diabetes, associated with complications such as heart attacks, strokes, and kidney failure, has necessitated the development of diverse, customized wearable sensors, particularly for the elderly. In this study, a fully integrated flexible sensor based on a PUC-CoNi-LDH@PANI nanocomposite is fabricated. This involves the direct growth of CoNi-double layer hydroxide (CoNi-LDH) through a facile template-free solvothermal treatment, followed by the vapor phase polymerization (VPP) of π-conjugated polyaniline (PANI) on a flexible electrospun polyurethane/chitosan (PUC) mat. Electrochemical studies indicate that the PUC-CoNi-LDH@PANI sensor exhibits ultrahigh sensitivity (2 187.62, 1 752.06 µA mm ^-1 cm^-2) across an acceptable linear range (0.001 to 3.70 mm) and has an extremely low detection limit (0.13 µm). The superior sensing performance is attributed to the synergistic effects of enhanced catalytic activity, dramatically enlarged surface area of CoNi-LDH nano-flake arrays, mass transfer capability, and improved conductivity due to PANI modification. Moreover, this novel, flexible, nanofiber-based sensor demonstrates excellent reliability for practical glucose detection in human sweat, thereby affirming its potential as a candidate for flexible microelectronics and as a top choice for flexible and wearable healthcare diagnostics systems.