title: Bead-based competitive fluorescence immunoassay for sensitive and rapid diagnosis of cyanotoxin risk in drinking water.
abstract: Due to the increased occurrence of cyanobacterial blooms and their toxins in drinking water sources, effective management based on a sensitive and rapid analytical method is in high demand for security of safe water sources and environmental human health. Here, a competitive fluorescence immunoassay of microcystin-LR (MCYST-LR) is developed in an attempt to improve the sensitivity, analysis time, and ease-of-manipulation of analysis. To serve this aim, a bead-based suspension assay was introduced based on two major sensing elements: an antibody-conjugated quantum dot (QD) detection probe and an antigen-immobilized magnetic bead (MB) competitor. The assay was composed of three steps: the competitive immunological reaction of QD detection probes against analytes and MB competitors, magnetic separation and washing, and the optical signal generation of QDs. The fluorescence intensity was found to be inversely proportional to the MCYST-LR concentration. Under optimized conditions, the proposed assay performed well for the identification and quantitative analysis of MCYST-LR (within 30 min in the range of 0.42-25 μg/L, with a limit of detection of 0.03 μg/L). It is thus expected that this enhanced assay can contribute both to the sensitive and rapid diagnosis of cyanotoxin risk in drinking water and effective management procedures.
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea.
authors.forename: Hye-Weon
authors.initials: HW
authors.lastname: Yu
authors.forename: Am
authors.initials: A
authors.lastname: Jang
authors.forename: Lan Hee
authors.initials: LH
authors.lastname: Kim
authors.forename: Sung-Jo
authors.initials: SJ
authors.lastname: Kim
authors.forename: In S
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001710:Biotin / Q000031:analogs & derivatives; D060766:Drinking Water; D004784:Environmental Monitoring / Q000379:methods*; D005453:Fluorescence; D007118:Immunoassay; D018189:Immunomagnetic Separation; D008280:Magnetics; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis* / Q000276:immunology; D046931:Microcystis / Q000737:chemistry; D011092:Polyethylene Glycols; D045663:Quantum Dots; D015203:Reproducibility of Results; D019809:Streptavidin; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D060766:Drinking Water; D008387:Marine Toxins; D052998:Microcystins; D014874:Water Pollutants, Chemical; D011092:Polyethylene Glycols; D001710:Biotin; D019809:Streptavidin; C057862:cyanoginosin LR