Toward a SPR imaging in situ system to detect marine biotoxin

Harmful Algal Blooms (HABs) are increasingly recognized as having profound effects upon the ecology of coastal waters and upon the economics of fisheries and aquaculture. HABs by contaminating shellfish with biotoxins affect human health and require effective surveillance and management programs to protect human consumers of seafood. Blooms of Pseudo-nitzschia producing a neurotoxin known as Domoic Acid (DA) are of increasing concern as their frequency and intensity increase rapidly. Although these toxic algal blooms represent a serious public health and economic problems, no cost-effective device, allowing the detection of dissolved DA in seawater is not yet available on the market. Surface Plasmon Resonance (SPR) biosensors have demonstrated their ability to detect small molecules at very low concentrations in real-time. We recently reported a rapid SPR biosensor inhibition assay to measure dissolved DA in the seawater matrix in-field deployment. Based on antibodies recognition, this system can detect DA at concentration over a range of 0.1-2 ng.mL(-1). However, this first prototype suffered from certain limitations. Multiplexing the assay increasing of the detection range, reproducibility and sample replicates are now required. Thus, a new biosensor based on SPR imaging (SPRi) technique was developed. The prototype was designed to meet high sensitivity, compactness and cost-efficiency requirements. The performances of this sensor were first studied in laboratory conditions, then it was deployed mesocosm facility. The new automated SPRi sensor showed promise for in situ detection of DA.