荧光免疫及磁免疫层析法检测莱克多巴胺的研究

Fluoroimmunoassay and Magnetic Lateral Flow Immunoassay for the Detection of Ractopamine

分别将量子点和超顺纳米磁珠作为荧光探针和磁信号探针应用于免疫反应中,构建了检测莱克多巴胺的荧光免疫和磁免疫层析的分析方法,并成功应用于尿液中莱克多巴胺的检测。两种方法均基于免疫竞争模式,在荧光免疫分析方法中,量子点偶联上识别莱克多巴胺的抗体,样品中莱克多巴胺和包被在ELISA板上莱克多巴胺的完全抗原竞争结合量子点,样品中莱克多巴胺的浓度越高,ELISA板上吸附的量子点越少,所测荧光强度值越低,该方法的检出限为1ng·mL-1,检测时间为4h。在磁免疫层析方法中,检测线上特异性捕获的纳米磁珠颜色的深浅和尿液中莱克多巴胺浓度成反比例关系,即莱克多巴胺的浓度越高,检测线的颜色越浅,该方法的定性检出限为10ng·mL-1,检测时间为15min。两种方法各有优缺点,基于量子点的荧光免疫分析法在痕量检测和定量分析方面具有优势,而磁免疫层析法更适合于现场快速检测。

A fluoroimmunoassay based on quantum dots（QDs）and a lateral flow immunoassay system based on the magnetic beads（MB）were constructed to detect ractopamine（RAC）in urine samples.The monoclonal antibody（Ab1）against RAC was conjugated with QDs or MB as detector reagent,respectively.They apply a competitive format using an immobilized RAC conjugate and free RAC present in samples.That is to say,the concentration of RAC in the sample was negative related to the fluorescense intensity of QDs or the color density of MB.Results showed that the limit of detection（LOD）of fluorescence immunoassay method is 1ng·mL-1 and analysis time is 4h,while the visual LOD was 10ng·mL-1 and analysis time was 15 min in magnetic lateral flow immunoassay system（MFLIS）.Taken into consideration of the advantages and disadvantages of the two methods,it was suitable for the trace detection of RAC using fluoroimmunoassay while it was appropriate for point-of-care tesing of RAC by MFLIS.