Electrochemical Flow-ELISA for Rapid and Sensitive Determination of Microcystin-LR Using Automated Sequential Injection System

Electrochemical Biosensors for Tracing Cyanotoxins in Food and Environmental Matrices

The adoption of electrochemical principles to realize on-field analytical tools for detecting pollutants represents a great possibility for food safety and environmental applications. With respect to the existing transduction mechanisms, i.e., colorimetric, fluorescence, piezoelectric etc., electrochemical mechanisms offer the tremendous advantage of being easily miniaturized, connected with low cost (commercially available) readers and unaffected by the color/turbidity of real matrices. In particular, their versatility represents a powerful approach for detecting traces of emerging pollutants such as cyanotoxins. The combination of electrochemical platforms with nanomaterials, synthetic receptors and microfabrication makes electroanalysis a strong starting point towards decentralized monitoring of toxins in diverse matrices. This review gives an overview of the electrochemical biosensors that have been developed to detect four common cyanotoxins, namely microcystin-LR, anatoxin-a, saxitoxin and cylindrospermopsin. The manuscript provides the readers a quick guide to understand the main electrochemical platforms that have been realized so far, and the presence of a comprehensive table provides a perspective at a glance.

Prediction of varying microcystins during non-thermal plasma oxidation of harvested microalgal biomass

By capturing intracellular microcystins (MCs) release from microalgal cell destruction and extracellular MCs oxidation, this study suggests a mathematical model explaining the simultaneous removal of microalgae and their toxins (MC-LR, -RR, and -YR) in non-thermal plasma (NTP) application. Although the suggested model was built based on simplified kinetic assumptions, it can reasonably predict the behavior of extracellular MCs in a harvested/concentrated slurry of microalgae taken from a blooming site. After 24 h of NTP treatment, the experimental reduction of extracellular MCs was recorded up to ∼77 %. Regressions based on the experimental data reveal the degradation rate (8.60 d^-1) and release rate (0.37 d^-1) of MCs, which provides the essential physicochemical information about intracellular MCs release by microalgal cell destruction. Simulation results help to develop safe and useful control over the simultaneous treatment of harvested microalgal biomass and toxins. This study further demonstrates that the suggested model contributes to predicting the variation of MCs in mass management of microalgal biomass for sustainable utilization.

Biosensing of microcystins in water samples; recent advances

Safety and quality of water are significant matters for agriculture, animals and human health. Microcystins, as secondary metabolite of cyanobacteria (blue-green algae) and cyclic heptapeptide cyanotoxin, are one of the main marine toxins in continental aquatic ecosystems. More than 100 microcystins have been identified, of which MC-LR is the most important type due to its high toxicity and common detection in the environment. Climate change is an impressive factor with effects on cyanobacterial blooms as source of microcystins. The presence of this cyanotoxin in freshwater, drinking water, water reservoir supplies and food (vegetable, fish and shellfish) has created a common phenomenon in eutrophic freshwater ecosystems worldwide. International public health organizations have categorized microcystins as a kind of neurotoxin and carcinogen. There are several conventional methods for detection of microcystins. The limitations of traditional methods have encouraged the development of innovative methods for detection of microcystins. In recent years, the developed sensor techniques, with advantages, such as accuracy, reproducibility, portability and low cost, have attracted considerable attention. This review compares the well-known of biosensor types for detection of microcystins with a summary of their analytical performance.