Rapid detection and quantification of microcystins in surface water by an impedimetric immunosensor

Exposure to cyanotoxins, particularly microcystins, in water reservoirs, is associated with hepatotoxicity and carcinogenesis and leads to acute and chronic damages. Consequently, many countries have imposed stringent regulations, limiting the allowed microcystins concentration in drinking water to < 1 mu g/L. Current methods for microcystins detection rely on laboratory-based methods requiring skilled personnel and labor-intensive preparation, which cannot provide a real-time measurement at the required sensitivity. Therefore, there is an imperative need for an on-site diagnostic tool providing a rapid quantitative determination of microcystins in surface water. We have developed an electrochemical biosensor based on the integration of specific antibodies with a biochip and a measurement platform and applied it in the detection of microcystin-LR, among the most toxic microcystins, by electrochemical impedance spectroscopy. Using the miniaturized platform, quantitative detection of microcystin-LR was feasible, exhibiting a broad dynamic range of five logarithmic concentrations and a detection limit of 3 ng/L, which is superior to currently employed surface-based immunoassays. More importantly, specific detection of microcystin-LR from models of cyanobacteria-contaminated water was also demonstrated. Based on our findings, we anticipate that electrochemical biosensors would be an essential tool in water monitoring and environmental diagnostics in the near future.

Automated summary

The development of an electrochemical biosensor for rapid quantitative detection of microcystins in water has shown superior sensitivity and specificity compared to current methods, demonstrating its potential as an essential tool for water monitoring and environmental diagnostics in the future.