Surface plasmon resonance-based detection of ladder-shaped polyethers by inhibition detection method

Progress in Plasmonic Sensors as Monitoring Tools for Aquaculture Quality Control

Aquaculture is an expanding economic sector that nourishes the world's growing population due to its nutritional significance over the years as a source of high-quality proteins. However, it has faced severe challenges due to significant cases of environmental pollution, pathogen outbreaks, and the lack of traceability that guarantees the quality assurance of its products. Such context has prompted many researchers to work on the development of novel, affordable, and reliable technologies, many based on nanophotonic sensing methodologies. These emerging technologies, such as surface plasmon resonance (SPR), localised SPR (LSPR), and fibre-optic SPR (FO-SPR) systems, overcome many of the drawbacks of conventional analytical tools in terms of portability, reagent and solvent use, and the simplicity of sample pre-treatments, which would benefit a more sustainable and profitable aquaculture. To highlight the current progress made in these technologies that would allow them to be transferred for implementation in the field, along with the lag with respect to the most cutting-edge plasmonic sensing, this review provides a variety of information on recent advances in these emerging methodologies that can be used to comprehensively monitor the various operations involving the different commercial stages of farmed aquaculture. For example, to detect environmental hazards, track fish health through biochemical indicators, and monitor disease and biosecurity of fish meat products. Furthermore, it highlights the critical issues associated with these technologies, how to integrate them into farming facilities, and the challenges and prospects of developing plasmonic-based sensors for aquaculture.

Potential threats posed by new or emerging marine biotoxins in UK waters and examination of detection methodology used in their control: brevetoxins

Regular occurrence of brevetoxin-producing toxic phytoplankton in commercial shellfishery areas poses a significant risk to shellfish consumer health. Brevetoxins and their causative toxic phytoplankton are more limited in their global distribution than most marine toxins impacting commercial shellfisheries. On the other hand, trends in climate change could conceivably lead to increased risk posed by these toxins in UK waters. A request was made by UK food safety authorities to examine these toxins more closely to aid possible management strategies, should they pose a threat in the future. At the time of writing, brevetoxins have been detected in the Gulf of Mexico, the Southeast US coast and in New Zealand waters, where regulatory levels for brevetoxins in shellfish have existed for some time. This paper reviews evidence concerning the prevalence of brevetoxins and brevetoxin-producing phytoplankton in the UK, together with testing methodologies. Chemical, biological and biomolecular methods are reviewed, including recommendations for further work to enable effective testing. Although the focus here is on the UK, from a strategic standpoint many of the topics discussed will also be of interest in other parts of the world since new and emerging marine biotoxins are of global concern.

Innovative detection methods for aquatic algal toxins and their presence in the food chain

Detection of aquatic algal toxins has become critical for the protection of human health. During the last 5 years, techniques such as optical, electrochemical, and piezoelectric biosensors or fluorescent-microsphere-based assays have been developed for the detection of aquatic algal toxins, in addition to optimization of existing techniques, to achieve higher sensitivities, specificity, and speed or multidetection. New toxins have also been incorporated in the array of analytical and biological methods. The impact of the former innovation on this field is highlighted by recent changes in legal regulations, with liquid chromatography-mass spectrometry becoming the official reference method for marine lipophilic toxins and replacing the mouse bioassay in many countries. This review summarizes the large international effort to provide routine testing laboratories with fast, sensitive, high-throughput, multitoxin, validated methods for the screening of seafood, algae, and water samples.

Detection of Rap1A as a yessotoxin binding protein from blood cell membranes

As is the case with other ladder-shaped polyether compounds, yessotoxin is produced by marine dinoflagellate, and possesses various biological activities beside potent toxicity. To gain a better understanding of the molecular mechanism for high affinity between these polyethers and their binding proteins, which accounts for their powerful biological activities, we searched for its binding proteins from human blood cells by using the biotin-conjugate of desulfated YTX as a ligand. By a protein pull-down protocol with use of streptavidin beads, a band of specifically binding proteins was detected in SDS-PAGE. HPLC-tandem mass spectrometry (MS/MS) indicated that Rap 1A, one of Ras superfamily proteins, binds to the YTX-linked resins. Western blotting and surface plasmon resonance experiments further confirmed that Rap1A specifically binds to YTX with the K(D) value around 4 μM.

Biological methods for marine toxin detection

The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in the legislations of many countries. Most marine toxin groups are detected by animal bioassays worldwide. Although this method has well known ethical and technical drawbacks, it is the official detection method for all regulated phycotoxins except domoic acid. Much effort by the scientific and regulatory communities has been focused on the development of alternative techniques that enable the substitution or reduction of bioassays; some of these have recently been included in the official detection method list. During the last two decades several biological methods including use of biosensors have been adapted for detection of marine toxins. The main advances in marine toxin detection using this kind of technique are reviewed. Biological methods offer interesting possibilities for reduction of the number of biosassays and a very promising future of new developments.

Use of biosensors as alternatives to current regulatory methods for marine biotoxins

Marine toxins are currently monitored by means of a bioassay that requires the use of many mice, which poses a technical and ethical problem in many countries. With the exception of domoic acid, there is a legal requirement for the presence of other toxins (yessotoxin, saxitoxin and analogs, okadaic acid and analogs, pectenotoxins and azaspiracids) in seafood to be controlled by bioassay, but other toxins, such as palytoxin, cyclic imines, ciguatera and tetrodotoxin are potentially present in European food and there are no legal requirements or technical approaches available to identify their presence. The need for alternative methods to the bioassay is clearly important, and biosensors have become in recent years a feasible alternative to animal sacrifice. This review will discuss the advantages and disadvantages of using biosensors as alternatives to animal assays for marine toxins, with particular focus on surface plasmon resonance (SPR) technology.