title: Homogeneous time-resolved fluoroimmunoassay of microcystin-LR using layered WS2nanosheets as a transducer.
abstract: A homogeneous time-resolved fluoroimmunoassay method for rapid and sensitive detection of microcystin-LR (MC-LR) in water samples was developed based on the interaction between water-soluble WS2nanosheets and the conjugate of MC-LR with a luminescent Eu3+complex BHHBCB-Eu3+(BHHBCB: 1,2-bis[4'-(1″,1″,1″,2″,2″,3″,3″-heptafluoro-4″,6″-hexanedion-6″-yl)- benzyl]-4-chlorosulfobenzene). The large lateral dimensions and high surface areas of two-dimensional layered WS2nanosheets enable easy adsorption of the MC-LR-BHHBCB-Eu3+conjugate, that lead to efficient quenching of the luminescence of Eu3+complex via energy transfer or electron transfer process. However, the addition of monoclonal anti-MC-LR antibody can induce the formation of MC-LR-BHHBCB-Eu3+/antibody immune complex, which prevents the interaction between WS2nanosheets and MC-LR-BHHBCB-Eu3+to result in the restoration of Eu3+luminescence. This signal transduction mechanism made it possible for analysis of the target MC-LR in a homogeneous system. The present method has advantages of rapidity and simplicity since the B/F (bound reagent/free reagent) separation steps, the solid-phase carrier and antibody labeling or modification process are not necessary. The proposed immunosensing system displayed a wide linear range, good precision and accuracy, and comparable sensitivity with a detection limit of 0.3 μg l-1, which satisfied the World Health Organization (WHO) provisional guideline limit of 1.0 μg l-1for MC-LR in drinking water.
authors.affiliation: State Key Laboratory of Fine Chemicals, School of Chemistry, Dalian University of Technology, Dalian 116024, People's Republic of China.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Qin
authors.forename: Yuanxiu
authors.initials: Y
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Song
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Ma
authors.forename: Jingli
authors.initials: J
authors.lastname: Yuan
mesh_terms: D060766:Drinking Water / Q000032:analysis; D005063:Europium / Q000737:chemistry; D015200:Fluoroimmunoassay / Q000379:methods*; D060106:Lakes / Q000737:chemistry; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis* / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D017973:Tungsten Compounds / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D060766:Drinking Water; D008387:Marine Toxins; D052998:Microcystins; D017973:Tungsten Compounds; D014874:Water Pollutants, Chemical; D005063:Europium; C057862:cyanoginosin LR