title: Development of a lateral flow fluorescent microsphere immunoassay for the determination of sulfamethazine in milk.
abstract: The fluorescent microsphere has been increasingly used as detecting label in immunoassay because of its stable configuration, high fluorescence intensity, and photostability. In this paper, we developed a novel lateral flow fluorescent microsphere immunoassay (FMIA) for the determination of sulfamethazine (SMZ) in milk in a quantitative manner with high sensitivity, selectivity, and rapidity. A monoclonal antibody to SMZ was covalently conjugated with the carboxylate-modified fluorescent microsphere, which is polystyrene with a diameter of 200 nm. Quantitative detection of SMZ in milk was accomplished by recording the fluorescence intensity of microspheres captured on the test line after the milk samples were diluted five times. Under optimal conditions, the FMIA displays a rapid response for SMZ with a limit of detection of as low as 0.025 ng mL(-1) in buffer and 0.11 μg L(-1) in milk samples. The FMIA was then successfully applied on spiked milk samples and the recoveries ranged from 101.1 to 113.6% in the inter-batch assay with coefficient of variations of 6.0 to 14.3%. We demonstrate here that the fluorescent microsphere-based lateral flow immunoassay (LFIA) is capable of rapid, sensitive, and quantitative detection of SMZ in milk.
authors.affiliation: College of Veterinary Medicine, China Agricultural University, Beijing Key Laboratory of Detection Technology for Animal-Derived Food Safety, Beijing Laboratory for Food Quality and Safety, Beijing, 100193, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Chen
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.forename: Han
authors.initials: H
authors.lastname: Zhang
authors.forename: Suxia
authors.initials: S
authors.lastname: Zhang
authors.forename: Weimin
authors.initials: W
authors.lastname: Shi
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Shen
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017022:Flow Injection Analysis / Q000295:instrumentation*; D005456:Fluorescent Dyes; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation*; D008863:Microspheres; D008892:Milk / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013418:Sulfamethazine / Q000032:analysis*
chemical_list: D000890:Anti-Infective Agents; D005456:Fluorescent Dyes; D013418:Sulfamethazine