Development of a High‐Sensitivity Electrochemical Biosensor for Domoic Acid and Its Cellular Impact on Human Stem and Neuron‐Like Cells

Domoic acid (DA) is an important environmental neurotoxin produced by certain types of marine algae and can accumulate in seafood such as anchovies, sardines, and mussels, which are considered healthy and widely consumed globally. One of the most important issues to consider is taking necessary measures to prevent water and marine pollution and conducting proper safety controls before consuming seafood. This study aimed to develop a high-sensitivity electrochemical biosensor system for detecting DA in seafood, aiding marine pollution monitoring. Additionally, the cytotoxicity of DA at the highest Food & Drug Administration (FDA)-permitted concentration and the concentrations determined in this study was examined on human cells. Gene expression related to cytotoxic response, DNA repair, and neurotoxicity was analyzed using amniotic fluid-derived mesenchymal stem cells (hAF-MSCs) and the human neuroblastoma cell line (SH-SY5Y) as neuron-like cell models. DA did not significantly affect the viability of hAF-MSCs or SH-SY5Y cells at 48-h exposure but slightly reduced viability at 100 μg/mL compared to the control group. DA activated the glutamate receptor in hAF-MSCs but not in SH-SY5Y cells. It also reduced DNA repair capacity in hAF-MSCs, though effects on viability and proliferation likely did not manifest within 48 h. There was no change in gene expression at 75 ng/mL of DA, which indicated the tolerable daily intake set by the FDA. The SH-SY5Y cells exhibited resistance against DA, indicating enhanced their DNA repair to prevent themselves against apoptosis and cell death. It is also supported by the upregulation of DNA repair-related genes and the membrane transporter gene ABCG2.