侧向流免疫层析-表面增强拉曼光谱联用技术超灵敏检测猪肉中喹乙醇残留

Surface-enhanced Raman spectroscopy based lateral flow immunoassay strip for ultrasensitive detection of olaquindox residues in pork

以具有强表面增强拉曼光谱(surface enhanced Raman scattering,SERS)活性的胶体金颗粒(Au nanoparticles,AuNPs)为基础,分别在其表面修饰4-氨基苯硫酚(PATP)和喹乙醇单克隆抗体(monoclonal antibody against olaquindox,OLA mAb),获得拉曼免疫探针OLA mAb-AuNPs-PATP.依据间接竞争原理组装侧向流免疫层析试纸,对各项实验条件进行优化,并借助拉曼光谱仪器,测定特征谱峰的拉曼信号强度计算出喹乙醇的浓度,由此建立了一种超灵敏定量检测猪肉中喹乙醇残留的侧向流免疫层析-表面增强拉曼光谱联用技术(SERS-LFA).结果表明:用该方法检测喹乙醇在0.0001~1.0 ng/mL范围内线性良好,检出限为0.31 pg/mL,回收率为93%~108%,相对标准偏差在3%~6%之间(n=3).并且对信号的重现性进行测定,在5个不同浓度下,每个浓度随机测定10个点的相对标准偏差分别为5.6%,6.3%,3.7%,4.8%和3.1%.该方法检测猪肉中喹乙醇具有简便、快速、超灵敏性、高特异性和良好重现性的优点.

Based on the colloidal gold particles with strong SERS activity,the Raman immunoprobe(OLA mAb-AuNPs-PATP)was prepared from AuNPs conjugated with a PATP or an OLA mAb.According to the principle of indirect competition,the lateral flow immunoassay strip was assembled,and the parameters of the assay were optimized.With the Raman spectrometer,the signal intensity of characteristic spectral peak was measured and the concentration of OLA was calculated.So the SERS-LFA was established for ultrasensitive detection of olaquindox residue in pork.The results show that the linear range of olaquindox detected by this method was 0.0001~1.0 ng/mL,and the limit of detection was 0.31 pg/mL.The recoveries of OLA from spiked pork samples ranged between 93%~108%,with relative standard deviations(RSD)from 3%to 6%(n=3).At five different concentrations,we randomly selected 10 different spots for each concentration and measured,the RSDs are 5.6%,6.3%,3.7%,4.8%and 3.1%,respectively.This method has the advantages of simplicity,rapidity,ultrasensitivity,high specificity and good reproducibility.