Electrochemical Biosensor on a Microfluidic Coculture Chip for Ovalbumin Detection

In this study, a microfluidic coculture electrochemical sensing platform was developed for the sensitive detection of ovalbumin (OVA). The chip integrated dual-layer serpentine microchannels separated by a porous PET membrane, enabling coculture and communication between Caco-2 and RBL-2H3 cells. OVA was quantified indirectly by monitoring interleukin-6 (IL-6) released during the cellular allergic response. The screen-printed electrode was modified by diazonium grafting, followed by AuNP electrodeposition for antibody immobilization and signal amplification. The integrated platform exhibited a linear response to OVA from 0.2 to 4 pg/mL, with a calibration equation of Ret(kΩ) = -7.450COVA(kΩ·mL/pg) + 47.342 (R2 = 0.998) and a detection limit of 0.161 pg/mL. A maximum electrochemical response was observed after 4 h of OVA stimulation, allowing dynamic monitoring of allergen-induced cellular responses. The proposed platform provides a sensitive and biomimetic strategy for response-oriented food allergen analysis.