Nanoarrays for in situ toxin analysis

The state-of-the-art in natural marine biotoxin analysis in seafood is quite diverse with substantive progress in moving away from the antiquated mouse bioassays. Future bioanalytical methods suitable for the industry require... [ view full abstract ]

The state-of-the-art in natural marine biotoxin analysis in seafood is quite diverse with substantive progress in moving away from the antiquated mouse bioassays. Future bioanalytical methods suitable for the industry require cost-effective approaches to compete with multi-analyte laboratory based analytical approaches such as mass spectrometry. Advancements are required whereby biosensors should detect diverse groups of contaminants as a single test. The difficulties of this approach with nanoarray platforms arise with regulatory limits and assay design. For marine and cyanobacterial toxins antibody based novel sensor methods offer model solutions. For natural toxins the design and application of broad specificity antibodies on multiplex and nanoarray platforms using a single combinational sample preparation offers this opportunity.  

Broad specificity antibodies to the marine and freshwater toxin targets have been produced and characterised. A planar waveguide immunoassay platform for the multiplex detection of these toxins has been developed. Toxin-protein conjugates were spotted onto sensor slides and molecular interactions between antibodies and conjugates were measured using secondary antibodies labelled with a fluorescent dye. The assays were optimised with regards sensitivity. The speed of the assay could be performed within 15 minutes. The sensitivity (IC₅₀) for each toxin group has been illustrated as 0.06, 0.42, 1.86, 1.40 and 0.19 ng/mL for saxitoxin, okadaic acid, domoic acid, microcystins and cylindrospermopsin in water samples. To date the assay also demonstrates high suitability for the detection of the emerging toxin tetrodotoxin in seafood samples in ten minutes.