磁敏传感器竞争免疫法检测牛奶中的氯霉素残留量

利用直接竞争免疫原理和巨磁致电阻效应,建立了磁敏生物传感器检测氯霉素的方法。制备氯霉素半抗原芯片,依次加入待测样品、生物素化抗体、链霉亲和素磁颗粒偶联物,使之发生竞争免疫反应,再利用传感器检测芯片上结合的磁颗粒数目。通过对检测条件的优化,建立了氯霉素浓度与磁颗粒数目的标准工作曲线。本方法的检测范围为0.05～100.0μg/L;检出限为50 ng/L;用于牛奶检测,回收率为95.97%～99.36%;批内相对标准偏差为0.8%～3.9%,批间相对标准偏差为1.1%～1.7%;与ELISA方法的一致相关系数达到0.98。本方法可在30 min内快速完成定量检测,为快速多靶标磁敏竞争免疫检测体系的建立提供了可行性。

Magnetoresistive Biosensor for Detection of Chloramphenicol Residue in Milk

Based on direct competitive immunoassay principle and giant magnetoresistance(GMR) effect,a novel method for detecting chloramphenicol(CAP) by magnetic biosensor has been developed.The sample,biotinylated anti-CAP monoclonal antibody,and streptavidin-beads conjugate were added onto the prepared CAP hapten chips one by one.Subsequently,competitive immune reaction happened and the number of beads bonded on chips was detected by magnetic biosensor.The standard curve was established by optimizing the detection condition.This method can be used to detect CAP in a range of 0.05-100.0 μg/L,detection limit of 50 ng/L.The analyte recoveries in milk samples ranged from 95.97% to 99.36%.The relative standard deviations ranged from 0.8% to 3.9% for intra-assay and 1.1% to 1.7% for inter-assay.The correlation coefficient between this method and ELISA was 0.98.Rapid quantitative detection could be accomplished within 30 minutes using this method.It provides feasibility for the establishment of rapid multi-target magnetic competitive immunoassay system.