State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
J Mater Chem B. 2020 Apr 29;8(16):3667-3675. doi: 10.1039/c9tb02776a.
Fluoroquinolones are synthetic antibiotics that are commonly used in animal husbandry, and the consumption of animal products with fluoroquinolone residues has imposed a serious threat to human health. Here, we report a plasmonic enzyme-linked immunosorbent assay (pELISA) method based on oxidative etching of silver nanoprisms (AgNPRs) for the quantitative and qualitative detection of danofloxacin (DAN), a fluoroquinolone antibiotic. AgNPRs that undergo colorimetric changes upon oxidative etching by H2O2 serve as the signal transducer in our design. An indirect competitive pELISA was constructed by introducing biotinylated monoclonal antibody (mAb), streptavidin and biotinylated glucose oxidase, which catalyzes the generation of H2O2 for etching AgNPRs. The quantitative detection limit of the proposed method was 0.24 ng mL-1 for DAN. The qualitative detection limit for DAN reached 0.32 ng mL-1, which was 32-fold lower than that of the assay using 3,3',5,5'-tetramethylbenzidine (TMB) as the signal transducer. The average recoveries of DAN in milk ranged from 103% to 121%, with a coefficient of variation of 0.6-3.41%. The recovery results were further confirmed using liquid chromatography-tandem mass spectrometry. In summary, the proposed AgNPR-etching pELISA exhibits high sensitivity, good accuracy and excellent reliability for the quantitative and qualitative detection of DAN in milk.
氟喹诺酮类药物是一种常用于畜牧业的合成抗生素，而食用含有氟喹诺酮残留的动物产品对人类健康构成了严重威胁。在这里，我们报告了一种基于银纳米棒（AgNPRs）氧化刻蚀的等离子体酶联免疫吸附测定（pELISA）方法，用于定量和定性检测氟喹诺酮类抗生素丹诺氟沙星（DAN）。AgNPRs 在 H2O2 的氧化刻蚀作用下发生颜色变化，可作为我们设计中的信号转导器。通过引入生物素化单克隆抗体（mAb）、链霉亲和素和生物素化葡萄糖氧化酶，构建了间接竞争 pELISA，后者可催化 H2O2 的生成，从而刻蚀 AgNPRs。该方法对 DAN 的定量检测限为 0.24 ng mL-1。DAN 的定性检测限达到 0.32 ng mL-1，比使用 3,3',5,5'-四甲基联苯胺（TMB）作为信号转导器的测定方法低 32 倍。DAN 在牛奶中的平均回收率在 103%至 121%之间，变异系数为 0.6-3.41%。使用液相色谱-串联质谱法进一步证实了回收结果。综上所述，所提出的 AgNPR 刻蚀 pELISA 对牛奶中 DAN 的定量和定性检测具有高灵敏度、良好的准确性和出色的可靠性。
