Development and single-laboratory validation of a pseudofunctional biosensor immunoassay for the detection of the okadaic acid group of toxins

Linda D. Stewart*, Philip Hess, Lisa Connolly, Christopher T. Elliott

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Citations (Scopus)
358 Downloads (Pure)

Abstract

A rapid analytical optical biosensor-based immunoassay was developed and validated for the detection of okadaic acid (OA) and its structurally related toxins from shellfish matrix. The assay utilizes a monoclonal antibody which binds to the OA group of toxins in order of their toxicities, resulting in a pseudofunctional assay. Single-laboratory validation of the assay for quantitative detection of OA determined that it has an action limit of 120 μg/kg, a limit of detection of 31 μg/kg, and a working range of 31−174 μg/kg. The midpoint on the standard matrix calibration curve is 80 μg/kg, half the current regulatory limit. Inter- and intra-assay studies of negative mussel samples spiked with various OA concentrations produced average coefficient of variation (CV) and standard deviation (SD) values of 7.9 and 10.1, respectively. The assay was also validated to confirm the ability to accurately codetect and quantify dinophysistoxin-1 (DTX-1), DTX-2, and DTX-3 from shellfish matrix. Alkaline hydrolysis was not required for the detection of DTX-3 from matrix. Excellent correlations with the data generated by the biosensor method and liquid chromatography/tandem mass spectrometry (LC/MS/MS) were obtained using a certified reference material (R2 = 0.99), laboratory reference material, and naturally contaminated mussel samples (R2 = 0.97). This new procedure could be used as a rapid screening procedure replacing animal-based tests for DSP toxins.

Original languageEnglish
Pages (from-to)10208-10214
Number of pages7
JournalAnalytical Chemistry
Volume81
Issue number24
Early online date23 Nov 2009
DOIs
Publication statusPublished - 15 Dec 2009

ASJC Scopus subject areas

  • Analytical Chemistry

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