title: Surface-enhanced fluorescence immunosensor using Au nano-crosses for the detection of microcystin-LR.
abstract: A surface-enhanced fluorescence (SEF) immunosensor for the detection of microcystin-LR was developed using Au nano-crosses as fluorescence enhancement nanoparticles and cy5 as a fluorescence label molecule. The SEF effects of cy5 in the proximity of Au nanorods and gold nano-crosses was investigated by using Au nanorods or nano-crosses coated negative-charged glass surfaces. Fluorescence measurements indicated that SEF was influenced by the size, shape and distribution of the Au nanoparticles, with an appropriate spacer layer between the Au nanoparticles and the cy5. The enhancement factor was from 2.3- to 35-fold. Under optimal conditions, the SEF immunosensor exhibited a good linear response at microcystin-LR concentrations of 0.02-16 ng mL(-1) (R(2)=0.9981). The limit of detection was 0.007 ng mL(-1) with little adsorption of microcystin-RR, microcystin-LW, and microcystin-LF. High microcystin-LR recoveries were obtained from naturally contaminated fish samples. The SEF immunosensor allows the reliable detection of microcystin-LR in seafood, and has potential in simple, sensitive detection applications.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 7214122, Jiangsu, PR China; Key Laboratory of Agro-food Safety and Quality of Ministry of Agriculture, Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, No. 12, Zhongguancun South Street, Beijing 100081, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 7214122, Jiangsu, PR China.
authors.forename: Jiadi
authors.initials: J
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 7214122, Jiangsu, PR China.
authors.forename: Longyun
authors.initials: L
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 7214122, Jiangsu, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi 7214122, Jiangsu, PR China. Electronic address: sxlzzz@jiangnan.edu.cn.
authors.forename: Xiulan
authors.initials: X
authors.lastname: Sun
authors.affiliation: Key Laboratory of Agro-food Safety and Quality of Ministry of Agriculture, Institute of Quality Standards and Testing Technology for Agro-products, Chinese Academy of Agricultural Sciences, No. 12, Zhongguancun South Street, Beijing 100081, PR China. Electronic address: qyzcaas@163.com.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Qian
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002232:Carbocyanines; D005456:Fluorescent Dyes; D005516:Food Microbiology; D006046:Gold; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D008387:Marine Toxins; D053768:Metal Nanoparticles / Q000648:ultrastructure; D052998:Microcystins / Q000032:analysis* / Q000276:immunology / Q000633:toxicity; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000648:ultrastructure; D017747:Seafood / Q000382:microbiology / Q000633:toxicity
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D008387:Marine Toxins; D052998:Microcystins; C085321:cyanine dye 5; D006046:Gold; C057862:cyanoginosin LR
keywords: Au nano-crosses; Microcystin-LR; Surface enhanced fluorescence immunosensor