Detection of Ciguatoxins and Tetrodotoxins in Seafood with Biosensors and Other Smart Bioanalytical Systems

Abstract

The emergence of marine toxins such as ciguatoxins (CTXs) and tetrodotoxins (TTXs) in non-endemic regions may pose a serious food safety threat and public health concern if proper control measures are not applied. This article provides an overview of the main biorecognition molecules used for the detection of CTXs and TTXs and the different assay configurations and transduction strategies explored in the development of biosensors and other biotechnological tools for these marine toxins. The advantages and limitations of the systems based on cells, receptors, antibodies, and aptamers are described, and new challenges in marine toxin detection are identified. The validation of these smart bioanalytical systems through analysis of samples and comparison with other techniques is also rationally discussed. These tools have already been demonstrated to be useful in the detection and quantification of CTXs and TTXs, and are, therefore, highly promising for their implementation in research activities and monitoring programs.

Automated Patch Clamp for the Detection of Tetrodotoxin in Pufferfish Samples

“…Immunochemical techniques provide a global response from all TTX and TTX analogues that cross-react with the antibody. Again, each TTX analogue cross-reacts with a higher or lower structural affinity, contributing at a higher or lower extent to the global response [23,75]. The TTX contents obtained with the APC were of the same order of magnitude as those provided by the immunochemical approaches.…”

“…Due to their origin, the distribution of VGSCs on the membranes of these cells is highly conserved, and this is interesting from an analytical point of view since they may provide toxicological responses closely related to the ones suffered in real poisoning events. However, the difficulties associated with cell culturing added to the dependence on animals as a source of cells from primary cultures reduce their applicability [23], especially when high throughput analysis is pursued and high cellular densities are required. Contrarily to primary cell cultures, immortalised cell lines may not express all receptors present in vivo.…”

“…Typically, neuroblastoma cell lines have been used to detect toxins of marine origin [19,20]. This is due to the presence in the cells of several targets that are normally affected by marine toxins and that may cause a loss in function or cell death, the endpoint of which is usually measured in many methods [21][22][23]. Among them, Neuro-2a cells are a particular type of neuroblastoma from mice that has been used for TTX detection [24,25].…”

Evaluation of Toxicity Equivalency Factors of Tetrodotoxin Analogues with a Neuro-2a Cell-Based Assay and Application to Puffer Fish from Greece

“…Many bacteria, such as Pseudomonas sp., Vibrio sp., and Alteromonas sp., have been observed to produce TTX, but the contribution of micro-organisms to TTX bioaccumulation in marine ecosystems is still not fully elucidated [ 8 , 9 ]. To date, more than 30 analogues of TTX have been described, with varying toxic potencies, many of which are detected in puffer fishes [ 10 ]. TTX and its analogues are known to selectively block the voltage-gated sodium channels (VSGCs).…”

Biosensors and Smart Analytical Systems in Food Quality and Safety: Status and Perspectives

“…Colour change was also used as an analytical strategy using aptamer-functionalised nanobeads by Yu Chen and co-workers [ 12 ], who developed an aptasensor for the determination of aflatoxin B1 in cereal samples, an analyte of great concern due to its toxicity. Two other very toxic molecules present in fish were the subject of the review proposed by Jaume Reverté and co-authors [ 13 ], while zearalenone was analysed in edible and medicinal coix seeds by Kaiyi Guan and co-workers, using a strategy based on an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) [ 14 ]. This method was applied to the determination of zearalenone in 122 batch coix seeds from different parts of China, showing that the occurrence of zearalenone is a universal problem in various districts in China.…”