在制备出镉离子单克隆抗体的基础上,首先运用柠檬酸钠还原法合成了胶体金,然后用胶体金标记抗体,得到检测探针;优化实验条件后,组装试纸条,样品中的镉与检测线上面的抗原竞争有限的金标抗体,通过观察检测线的颜色,确定检出限;最后检测方法的特异性和灵敏度,建立了一种快速检测水样中镉离子的竞争免疫层析试纸条方法.结果:方法的检出限为50 ng·mL-1,交叉反应结果表明,该抗体除与汞离子有交叉反应外,与其他金属离子(Zn2+、Cr3+、Pb2+、Cu2+、Ni2+、Al3+、Co2+、Fe3+、Mg2+、Ca2+和Ba2+)均无交叉反应.湖水样品中镉的加标实验结果显示与传统的酶联免疫分析方法有很好的相关性.建立的胶体金免疫层析试纸条方法可以特异、快速地检测水样中的重金属镉离子,在10 min左右可以得到结果,适合用于现场检测.%In this work,based on the monoclonal antibody(mAb)which can specifically recognize individual Cd-EDTA,a competi-tive immunochromatographic assay(ICA)using colloidal gold-mAb probe for rapid and direct detection of Cd2+ in water samples was described. Cd2+ in standard/sample solution competed with the coating antigen immobilized on the test line for limited mAb on the immunoprobe. The assay for Cd2+ was completed within 10 min. The visual detection of limit(LOD)of the ICA for Cd2+ was 50 ng·mL-1 . There was no cross-reactivity with other metal ions except Hg2+. Real water samples spiked with different concentrations of Cd2+ were measured by ICA and the results were highly consistent with those obtained from enzyme-linked immunosorbent assay (ELISA). It was demonstrated that the proposed ICA was an applicable method for rapid and direct detection of Cd2+ on-site.
展开▼
