High-performance and -efficiency cardiomyocyte-based potential biosensor for temporal-specific detection of ion channel marine toxins

Paralytic shellfish toxins (e.g., saxitoxin, STX; gonyautoxin-2, GTX-2) and tetrodotoxin (TTX) are highly toxic and widely distributed ion channel marine toxins which specifically block the voltage-dependent sodium channels (VDSCs), causing great harm to human health. It is urgent to exploit new detection methods with high specificity and high efficiency. Here, a portable high-throughput cardiomyocyte-based potential biosensor was established with cardiomyocytes, a 16-well microelectrodes (MEs) sensor and a robust 32-channel recording system, which presented high-quality and high-consistency extracellular field potential (EFP) signals in each well with a long duration of 80 h. The feature parameters, including firing rate (FR), spike amplitude (SA), spike slope (SS), spike duration (SD) and field potential duration (FPD), were extracted from EFP to quantitatively assess the toxic effects of these ion channel toxins. Importantly, the biosensor showed temporal specificity and parametric selectivity under toxin treatments, and FR, SS and SD were the optimal parameters to STX, TTX and GTX-2, respectively. This biosensor can rapidly detect 0.29 ng/mL STX, 0.30 ng/mL TTX and 0.16 ng/mL GTX-2 within 5 min, 10 min and 15 min, respectively. Thus, our novel multi-well cardiomyocyte-based biosensor will be a promising tool for high-effective detection of ion channel toxins.