Recent Advances in Electrochemical and Optical Point-of-Care Testing for Marine Biotoxin Detection

Marine biotoxins (MBs) are harmful metabolites produced by algal species affect marine organisms and pose significant risks to marine ecosystems and human health. MBs accumulate in finfish and shellfish, resulting in over 20,000 foodborne poisoning cases annually. Rapid and sensitive MBs detection methods are urgently required to ensure food safety and protect the environment. Mouse bioassays and sophisticated testing techniques such as liquid chromatography-mass spectrometry, high-pressure liquid chromatography, and X-ray photoelectron spectroscopy are used for detecting MBs, but are limited by high cost and time consumption. Advantageously, electrochemical and optical immunoassays offer high portability, sensitivity, and potential for real-time monitoring. Advancements in point-of-care testing (POCT) systems using biosensing technologies renders ideal for detecting MBs in various food and environmental matrices. This review provides an overview of MBs, including their classification, source, and toxicity. Understanding the properties and applications of various types of MBs is essential for their effective detection via optical and electrochemical sensing. This review examines different methods of detecting MBs in seafood, including the use of enzymes, immunoassays, peptides, DNA, molecular imprinted polymers, and antigen–antibody pairs, and analysis using electrochemical and optical assays over the last five years. Sensing assays can be utilized in user-friendly tools, such as paper, microfluidic chips, smartphone-based POCT, and lateral-flow devices. Prospective directions for developing assays to facilitate the sensitive and on-site detection of MBs are proposed. This review provides a comprehensive overview of the technologies available for aiding researchers and doctors in selecting the most suitable methods of MBs detection.