Paralytic shellfish poisoning detection by surface plasmon resonance-based biosensors in shellfish matrixes

Area of Science:

• Analytical Chemistry
• Biosensor Technology
• Food Safety

Background:

• Paralytic Shellfish Poisoning (PSP) poses a significant human health risk.
• Current detection methods like the mouse bioassay have ethical and technical limitations.
• Development of rapid and reliable alternative detection methods is crucial.

Purpose of the Study:

• To develop and validate a novel Surface Plasmon Resonance (SPR) biosensor inhibition assay for detecting PSP toxins.
• To evaluate the performance of the SPR biosensor assay using various shellfish matrices and extraction methods.
• To compare the SPR biosensor assay with established methods (mouse bioassay, HPLC) for PSP toxin quantification.

Main Methods:

• An SPR biosensor inhibition assay was developed using an anti-GTX2/3 antibody (GT13-A) and a saxitoxin-CM5 chip.
• The assay quantified multiple PSP toxins (STX, dcSTX, GTX2/3, dcGTX2/3, GTX5, C1/2) in the range of 2-50 ng/mL.
• Five shellfish matrices (mussels, clams, cockles, scallops, oysters) were extracted using five different methods to assess interference and optimize sample preparation.

Main Results:

• Ethanol and acetic acid/heat extracts showed adequate performance with minimal interference and good surface regeneration.
• Hydrochloric acid/heat extracts (AOAC mouse bioassay method) caused surface regeneration issues.
• The ethanol extraction method, with calibration curves in blank matrix extracts, yielded the best results, including an STX recovery rate of 60.52+/-3.72%.

Conclusions:

• The developed GT13-A-STX chip inhibition assay is capable of detecting PSP toxins in shellfish using ethanol extracts.
• The assay demonstrates sufficient sensitivity to quantify toxins within the European regulatory limit (80 µg/100 g).
• This SPR biosensor technology shows promise as an effective screening assay for PSP toxins, offering an alternative to conventional methods.