Surface Plasmon Resonance Biosensor for Determination of Tetrodotoxin: Prevalidation Study

Abstract

Abstract A label-free surface plasmon resonance biosensor method was applied to determine tetrodotoxin (TTX) in pufferfish matrixes using an antibody inhibition assay format. A prevalidation study was conducted to demonstrate the assay performance characteristics, such as selectivity, LOD, LOQ, repeatability, reproducibility, and accuracy. Three participating laboratories reported standard curves in buffer and pufferfish matrix. A set of blind samples with TTX spiked into buffer as well as in 10 pufferfish extract were analyzed. Additionally, three blind naturally contaminated samples were analyzed, and the results were compared to those obtained using a reference method (HPLC/electrospray ionization-selected reaction monitoring-MS). The developed method was demonstrated to be capable of detecting TTX in pufferfish matrix standard samples in a broad concentration range (29000 ng/mL) with an LOD of 1.5 ng/mL. Between-laboratory recovery values were in the range of 51190 with a mean of 107, and 64180 with a mean of 103 for TTX-spiked samples in buffer and pufferfish matrix, respectively. Between-laboratory recoveries were in the satisfactory range of 101119 for naturally contaminated samples. This robust, rapid, and noninvasive method may serve as an attractive alternative to established methods for detection of TTX in pufferfish extracts.