Saxitoxin (STX), an exceptionally potent marine toxin for which no antidote is currently available, is produced by methanogens and cyanobacteria. This poses a significant threat to both shellfish aquaculture and human health. Consequently, the development of a rapid, highly sensitive STX detection method is of great significance. The objective of this research is to create a novel approach for identifying STX. Therefore, amplified luminescent proximity homogeneous assay (AlphaLISA) was established using a direct competition method based on the principles of fluorescence resonance energy transfer and antigen-antibody specific binding. This method is sensitive, rapid, performed without washing, easy to operate, and can detect 8-128 ng/mL of STX in only 10 min. The limit of detection achieved by this method is as low as 4.29 ng/mL with coefficients of variation for the intra-batch and inter-batch analyses ranging from 2.61% to 3.63% and from 7.67% to 8.30%, respectively. In conclusion, our study successfully establishes a simple yet sensitive, rapid, and accurate AlphaLISA method for the detection of STX which holds great potential in advancing research on marine biotoxins.
Keywords: amplified luminescent proximity homogeneous assay; biotoxin; immunoassay; paralytic shellfish poisoning; saxitoxin; shellfish.