Novel research on okadaic acid field-based detection using cell viability biosensor and Bionic e-Eye

•A novel bioanalysis method was developed for OA rapid spot detection.•CVB was constructed by combing living cells and CCK-8, and had biotoxicity evaluation ability.•Adherent cell and suspension cell both applied to CVB construction conveniently.•Bionic e-Eye realized acquisition, analysis, storage, display and sharing to data in real time.•The biosensing system detected OA in high sensitivity and high specificity. A novel bioanalysis method for sensitive, rapid and field-based detection of okadaic acid (OA) is in great demand for environmental monitoring and food security. In this study, we reported a biosensing system consisting of a smartphone-based system and cell viability biosensor (CVB) for OA spot fast detection. CVB was constructed by combing living cells and cell counting kit (CCK-8). Thereinto, living cells could be used as reagent without adherent culture on the device surface, and adherent cells and suspension cells were both applicable for cell type selection. The smartphone-based system – bionic electronic eye (Bionic e-Eye) was composed of portable illumination provider and smartphone. The homemade application program (App) – iPlate Monitor integrated the software functions of real-time image acquisition and analysis, data display and storage and instant data sharing. In the measurement, the system was demonstrated to detect OA at concentration as low as 3.4083μg/L and 13.4456μg/L by using HepG2 and THP-1 cells, respectively. In addition, this system distinguished OA versus different marine toxins such as gonyautoxin2&3 (GTX2&3) and brevetoxin-2 (PbTx-2) in high specificity. Consequently, the smartphone-based biosensing platform provided a convenient, low-cost, easy-to-use and efficient approach for spot rapid detection of marine toxins such as OA.