novel and sensitive fluorescence immunoassay for the detection of fluoroquinolones in animal-derived foods using upconversion nanoparticles as labels

• Published in: Analytical and bioanalytical chemistry Vol. 407; no. 28; pp. 8487 - 8496
• Main Authors: Hu, Gaoshuang, Sheng, Wei, Zhang, Yan, Wu, Xuening, Wang, Shuo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2015; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Animal-based foods; Animals; Anti-Bacterial Agents - isolation & purification; antibiotic residues; Antibodies, Monoclonal - chemistry; Antigens; Arsenic; Bioassays; Biochemistry; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; detection limit; ELISA; emissions factor; enzyme-linked immunosorbent assay; Erbium - chemistry; Fluorescence; Fluorescence Resonance Energy Transfer - methods; Fluorescent Antibody Technique - methods; Fluorescent Antibody Technique - standards; Fluoroquinolones - isolation & purification; Food; Food Analysis - instrumentation; Food Analysis - methods; food contamination; Food Contamination - analysis; Food Science; Foods; Fourier transforms; Heavy metals; Humans; Immunoassay; Immunoconjugates - chemistry; Laboratory Medicine; Limit of Detection; Meals; Meat Products - analysis; Milk; Milk - chemistry; Monitoring/Environmental Analysis; Monoclonal antibodies; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Neurotoxins; Norfloxacin; polystyrenes; Polystyrenes - chemistry; Probes; Pyrolysis; quantitative analysis; Reagents; Research Paper; Toxicity; Upconversion; Ytterbium - chemistry; China; United States > US; Japan; Fluoroquinolones; Fluorescence immunoassay; Animal-derived foods; Upconversion nanoparticles
• ISSN: 1618-2642; 1618-2650; 1618-2650
• DOI: 10.1007/s00216-015-8996-4

A novel fluorescence immunoassay to detect fluoroquinolones in animal-derived foods was developed for the first time by use of upconversion nanoparticles as signal-probe labels. The bioassay system was established by the use of coating-antigen-modified polystyrene particles as immune-sensing probes for separation and anti-norfloxacin monoclonal antibody conjugated with carboxyl-functionalized NaYF₄:Yb,Er upconversion nanoparticles which were prepared via a pyrolysis method and a subsequent ligand exchange process as fluorescent-signal probes (emission intensity recorded at 542 nm with excitation at 980 nm). Under optimized conditions, detection of fluoroquinolones was performed easily. The detection limit of this fluorescence immunoassay for norfloxacin, for example, was 10 pg mL⁻¹, within a wide linear range of 10 pg mL⁻¹ to 10 ng mL⁻¹ (R ² = 0.9959). For specificity analysis, the data obtained indicate this method could be applied in broad-spectrum detection of fluoroquinolones. The recoveries of norfloxacin-spiked animal-derived foods ranged from 82.37 to 132.22 %, with coefficients of variation of 0.24–25.06 %. The extraction procedure was rapid and simple, especially for milk samples, which could be analyzed directly without any pretreatment. In addition, the results obtained with the method were in good agreement with those obtained with commercial ELISA kits. The fluorescence immunoassay was more sensitive, especially with regard to the detection limit in milk samples (0.01 ng mL⁻¹ for norfloxacin): it was 50-fold more sensitive than commercial ELISA kits (0.5 ng mL⁻¹ for norfloxacin). The results show the proposed fluorescence immunoassay was facile, sensitive, and interference free, and is an alternative method for the quantitative detection of fluoroquinolone residues in animal-derived foods.