Automated Online Optical Biosensing System for Continuous Real-Time Determination of Microcystin-LR with High Sensitivity and Specificity: Early Warning for Cyanotoxin Risk in Drinking Water Sources

• Published in: Environmental science & technology 2013-05, Vol.47 (9), p.4434-4441
• Main Authors: Shi, Han-Chang, Song, Bao-Dong, Long, Feng, Zhou, Xiao-Hong, He, Miao, Lv, Qing, Yang, Hai-Yang
• Format: Article
• Language: English
• Subjects: Analysis methods; Antibodies, Monoclonal - immunology; Applied sciences; Automation; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Drinking water; Drinking Water - analysis; Drinking water and swimming-pool water. Desalination; Eutrophication; Exact sciences and technology; Fluorescence; Fundamental and applied biological sciences. Psychology; Limit of Detection; Methods. Procedures. Technologies; Microcystins - analysis; Microcystins - immunology; Natural water pollution; Pollution; Public health; Risk Assessment; Toxicity; Various methods and equipments; Water Pollutants, Chemical - analysis; Water pollution; Water treatment and pollution
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es305196f

The accelerated eutrophication of surface water sources and climate change have led to an annual occurrence of cyanobacterial blooms in many drinking water resources. To minimize the health risks to the public, cyanotoxin detection methods that are rapid, sensitive, real time, and high frequency must be established. In this study, an innovative automated online optical biosensing system (AOBS) was developed for the rapid detection and early warning of microcystin-LR (MC-LR), one of the most toxic cyanotoxins and most frequently detected in environmental water. In this system, the capturing molecular MC-LR-ovalbumin (MC-LR-OVA) was covalently immobilized onto a biochip surface. By an indirect competitive detection mode, samples containing different concentrations of MC-LR were premixed with a certain concentration of fluorescence-labeled anti-MC-LR-mAb, which binds to MC-LR with high specificity. Then, the sample mixture was pumped onto the biochip surface, and a higher concentration of MC-LR led to less fluorescence-labeled antibody bound onto the biochip surface and thus to lower fluorescence signal. The quantification of MC-LR ranges from 0.2 to 4 μg/L, with a detection limit determined as 0.09 μg/L. The high specificity and selectivity of the sensor were evaluated in terms of its response to a number of potentially interfering cyanotoxins. Potential interference of the environmental sample matrix was assessed by spiked samples, and the recovery of MC-LR ranged from 90 to 120% with relative standard deviation values