Recent Advances in Biosensor-Based Detection of Cyanotoxins in Aquatic Environments
Shivangi Rao
Department of Forensic Science, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, India.
Animesh Kumar Tiwari
Department of Forensic Science, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, India.
Shubhra Shree Gajbhiye
Department of Forensic Science, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, India.
Chanchal Kumar *
Department of Forensic Science, Guru Ghasidas Vishwavidyalaya, Bilaspur, Chhattisgarh, India.
*Author to whom correspondence should be addressed.
Abstract
The increasing frequency and geographic expansion of harmful cyanobacterial blooms have intensified global concerns regarding cyanotoxin contamination in freshwater systems and the associated risks to public health and ecosystem stability. Effective surveillance requires sensitive, selective, and reliable detection methods capable of addressing structurally diverse toxins, including microcystins, cylindrospermopsin, anatoxins, saxitoxins, and β-N-methylamino-L-alanine. This review describes the classification, global distribution, and toxicological significance of major cyanotoxins and critically evaluates current and emerging detection strategies. Conventional chromatographic techniques, particularly liquid chromatography–tandem mass spectrometry (LC–MS/MS), remain the reference standard due to their high sensitivity, structural specificity, and multi-toxin quantification capability, while high-resolution mass spectrometry enables non-target screening and identification of novel toxin variants. Immunological assays and protein phosphatase inhibition assays are examined as rapid and cost-effective screening tools, although their analytical limitations are discussed. The review highlights advances in biosensor technologies, including electrochemical immunosensors, aptamer-based sensors, molecularly imprinted polymer sensors, surface plasmon resonance systems, surface-enhanced Raman spectroscopy, microfluidic lab-on-a-chip platforms, multiplexed sensor arrays, and lateral flow immunoassays, emphasizing their sensitivity, portability, and potential for real-time monitoring. Comparative evaluation of detection limits and operational characteristics demonstrates that no single technique satisfies all requirements of ultra-trace sensitivity, structural confirmation, cost-effectiveness, portability, and multiplex capability. Therefore, an integrated tiered monitoring framework combining rapid screening tools with confirmatory mass spectrometric analysis is recommended. Continued methodological innovation and harmonization will be essential to strengthen cyanotoxin surveillance under evolving environmental and climatic pressures.
Keywords: Cyanotoxins, harmful algal blooms, LC–MS/MS, high-resolution mass spectrometry, biosensors, aptasensors, lateral flow immunoassay, water quality monitoring, early-warning systems, environmental risk assessment