Detection of diarrhetic shellfish poisoning toxins using high-sensitivity human cancer cell-based impedance biosensor

Diarrhetic shellfish poisoning (DSP) toxin is a dangerous contamination in seafood worldwide that can threaten human health and fishing. A large number of animal bioassays and chemical analytical methods are employed for DSP toxin detection. However, these toxin detection methods are low-throughput and high-cost which hamper their wide applications. In this study, HeLa and HepG2 cell lines were selected as the sensitive elements to establish the CIBs for monitoring the cytotoxicity induced by a representative DSP toxin, okadaic acid (OA). The limit of detection (LOD) of HeLa- and HepG2-based biosensors are 10.2 μg/L and 3.3 μg/L, respectively, which are both lower than the conventional cell-based assay (21.2 μg/L of HeLa cells and 9.8 μg/L of HepG2 cells). The half maximal inhibitory concentration (IC50) values of OA in HeLa and HepG2 cells which were obtained from CIB (49.9 ± 4.9 and 39.2 ± 4.3 μg/L) are both lower than Cell Counting Kit-8 assay (CCK8) (62.7 ± 7.1 and 45.8 ± 6.7 μg/L). Besides, CIB measurement presents good correlation with mouse bioassay (MBA) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In summary, all the results indicate that the CIB technology had great potential to be an effective complement in DSP toxins detection.