An electrochemical biosensor based on antifouling conductive hydrogel for umami detection in complex fish matrices

Bionic taste electrochemical sensors are crucial for the detection of flavor substances due to their sensitivity and biomimetic sensing capabilities. However, nonspecific fouling in complex food matrices limits accuracy. Herein, we developed an antifouling conductive hydrogel-based bionic umami sensor by integrating a zwitterionic polymer matrix with a conductive AuNPs/MXene framework. The zwitterionic hydrogel provided strong hydration and charge balance to suppress nonspecific protein adsorption, while AuNPs/MXene increased electroactive surface area and offered active sites for umami receptor immobilization. The sensor exhibited outstanding antifouling performance, with low signal variation (0.18%-4.42%) under fouling conditions, thereby enabling the monitoring of storage-dependent variations in overall umami-related response of fish samples. It exhibited a wide linear range (10^-12-10^-4 M) and an ultralow detection limit of 0.33 pM. This work provides an effective strategy for robust taste sensing in fouling environments and lays a foundation for correlating receptor-mediated signals with key umami markers in real samples.