量子点标记免疫亲和凝胶柱快速检测动物组织中恩诺沙星

Rapid Detection of the Enrofloxacin Reduce in Animal Tissues Using Immunophilic Gel Column of Quantum Dots Tags

目的:建立一种检测动物组织中残留的兽药恩诺沙星(ENR)的量子点标记免疫亲和凝胶柱快速检测新方法。方法:将恩诺沙星特异性抗体偶联到溴化氢活化的琼脂糖凝胶上,制备抗体胶,将抗体胶装入标准的1mL SPE固相萃取柱制成恩诺沙星免疫亲和凝胶检测柱。采用混合酸酐法制备恩诺沙星包被抗原(ENR-OVA),采用活化酯法将ENR-OVA偶联到水溶性量子点(QDs)上制备荧光信号探针QDs-OVA-ENR。将待测样品和荧光信号探针QDs-OVA-ENR分别加入检测柱中,基于抗原抗体的竞争结合反应,样品中的恩诺沙星和荧光信号探针QDs-OVA-ENR竞争结合检测柱中抗体。通过目测检测柱体的荧光强弱,定性半定量检测恩诺沙星的含量。结果:该量子点标记恩诺沙星免疫亲和凝胶检测柱的检测限(LOD)为2μg/L,对食源性动物组织样品的检测限为20μg/kg。检测过程不超过5 min。结论:该方法操作简便,灵敏度高,检测时间短,结果易于判断,可满足食源性动物组织中恩诺沙星残留的现场快速检测要求。

Objective： A new gel-based immunoassay using quantum dots as the fluorescence label was developed for rapid detection of the enrofloxacin（ENR） reduce in animal tissues. Methods： The specific anti-enrofloxacin antibody was conjugated to CNBr-activated Sepharose 4 B gel to prepare the anti-enrofloxacin antibody coupled gel. The gel-based test column in an empty SPE cartridge（1 mL） consisted of a test layer containing anti-enrofloxacin antibody coupled gel. The enrofloxacin was conjugated to OVA according to the mixed acid anhydride method to prepare the coating antigen（ENROVA）. The fluorescent signal probe（QDs-OVA-ENR） is prepared by coupling ENR-OVA to water-soluble quantum dots through activated ester method. Based on the direct competitive immuno-reaction, the test results could be evaluated visually according as fluorescence intensity. Results： The limit of detection（LOD） of this assay in assay buffer was 2 μg/L, and the limit of detection of assay for enrofloxacin in edible animal tissue samples was 20 μg/kg. And the whole detection process could be completed within 5 min. Conclusion： The gel-based visual immunoassay using quantum dots as the fluorescence label allows for simple, sensitive, time-saving, rapid detection of enrofloxacin residues in animal tissues.