Detection of microcystins in environmental samples using surface plasmon resonance biosensor

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biotechnology

Background:

• Microcystins (MCs) are potent toxins produced by cyanobacteria, posing risks to aquatic ecosystems and human health.
• Accurate and rapid detection of MCs is crucial for environmental monitoring and public safety.
• Conventional methods like ELISA, while sensitive, can be time-consuming and require multiple steps.

Purpose of the Study:

• To develop and validate an indirect inhibitive surface plasmon resonance (SPR) immunoassay for microcystins (MCs) detection.
• To evaluate the performance characteristics of the SPR immunoassay, including its quantitative range, reusability, and assay time.
• To assess the applicability of the SPR biosensor for detecting MCs in real environmental samples.

Main Methods:

• Development of an indirect inhibitive SPR immunoassay using a bioconjugate of MC-LR and bovine serum albumin (BSA) immobilized on a CM5 sensor chip.
• Monitoring of specific immunoreactions via a BIAcore 3000 biosensor by injecting premixtures of MC-LR standards (or samples) and monoclonal antibody (mAb).
• Quantification of MCs based on signal intensity correlating with decreasing MC concentration.

Main Results:

• The developed SPR immunoassay demonstrated a wide quantitative range of 1-100 microg L(-1) for MCs detection.
• The SPR sensor chip exhibited excellent reusability, maintaining binding activity after 50 regeneration cycles.
• Assay completion time was significantly reduced to 50 minutes, including preincubation and analysis, without requiring multiple steps.
• SPR biosensor results for environmental samples showed good agreement with conventional ELISA.

Conclusions:

• The SPR biosensor offers significant advantages for MCs detection, including reusability, speed, and simplified assay procedure.
• This method provides a robust alternative to traditional assays for MCs monitoring.
• The SPR biosensor holds potential for development into a field-portable device for real-time, on-site MCs monitoring.