将达氟沙星多克隆抗体和条形码DNA链同时修饰在金纳米颗粒表面用于制备纳米金复合探针（NP），达氟沙星单克隆抗体与磁性颗粒相结合制备磁性探针（MMP），待上述两种探针制备成功后与达氟沙星标准品进行杂交反应，同时发挥磁场作用固定MMP，除去未结合的NP探针，最后将标记在金纳米复合探针上的DNA链释放出来，对收集释放的DNA链应用微孔板银染的生物条形码技术进行检测间接得到达氟沙星的残留量，该检测方法不需要昂贵的仪器设备，普通实验室利用酶标仪即可完成全部实验操作，操作简单，检测速度快，其检测灵敏度要优于传统的酶联免疫吸附法。结果表明，在0.05~50 ng/mL范围内检测达氟沙星的最低检出限IC15为3.62 ng/mL，其检测灵敏度是常规免疫检测方法的100倍。本方法实现了对达氟沙星残留的超高灵敏度检测，同时本方法也可应用于其它类抗生素的高效快速检测，因此，本方法的建立具备一定的实用性。

The danofloxacin polyclonal antibody and barcoded DNA strand were simultaneously modified on the surface of gold nanoparticles to prepare gold nanocomposite probe (NP). The magnetic probes (MMPs) were prepared through combining the monoclonal antibody and magnetic particles. After the above two probes are successfully prepared, the hybridization reaction was carried out with the standard, danofloxacin. At the same time, the magnetic field was used to immobilize MMP and remove the unbound NP probe. Finally, the DNA strands labeled on the gold nanocomposite probe were released, and the collected and released DNA strands were detected by microplate silver-stainedbio-barcode technology to obtain indirectly the residual amount of danofloxacin. The detection method does not require expensive equipment, and ordinary laboratories can complete all the experimental operations by using the microplate reader. The operation is simple, the detection is fast, and the detection efficiency is higher than that of traditional ELISA. The results showed that the limit of detection IC15 was 3.62 ng/mL for danofloxacin in the range of 0.05~50 ng/mL, with the detection sensitivity being 100 times that of conventional immunoassay. This method realizes ultra-highly sensitive detection of danofloxacin residue, and can be applied to the rapid detection of other antibiotics. Therefore, the established method is reasonably practicable.

河北省重点研发计划项目（19225504D）；河北省研究生创新资助项目（CXZZSS2021125）；河北省高校百名优秀创新人才支持计划（Ⅲ）（SLRC2017019）；河北北方学院博士基金项目(12995545)