Shi Chenggang, Zhao Suqing, Zhang Kun, Hong Guobao, Zhu Zhenyu
The Third Affiliated Hospital of Sun Yat-sen University of Medical Sciences, Guangzhou 510630, China.
J Environ Sci (China). 2008;20(11):1392-7. doi: 10.1016/s1001-0742(08)62238-x.
Methamidophos (Met) is a broad spectrum organophosphorus insecticide and acaricide. Even a trace of its residue is harmful to humans and many animals. In this study, the synthesis and identification of colloidal gold particles and antibody-colloidal gold conjugates were performed, and the preparation of colloidal gold immunochromatography strip was conducted for detection of Met residue. The size of colloidal gold particles was checked using a transmission electron microscope (TEM). The formation of antibody-colloidal gold conjugates was monitored by UV/Vis spectroscopy. The preparation of colloidal gold immunochromatography strips, analysis of Met standard solutions, and other four pesticides and vegetable samples were operated with common methods and principals. The TEM images showed the average diameter of colloidal gold particles was almost the same size: approximately 40.0 nm in diameter. For the conjugation of colloidal gold and monoclonal antibody (MAb), 0.03 mg/ml of MAb was confirmed to be the minimum amount for stabilization of colloidal gold. With the prepared colloidal gold immunochromatography test strip to determine the standard Met solution, the results demonstrated a detection limit of approximately 1.0 mg/ml. Cross-reaction indicated that the strip had a high specificity to Met. The results of 10 green vegetable sample tests confirmed that one sample was positive by HPLC analysis. There was evidence to suggest that colloidal gold particles and antibody-colloidal gold conjugates were synthesized successfully. The prepared colloidal gold immunochromatography strip was applicable for preliminary screening of Met residue.
甲胺磷（Met）是一种广谱有机磷杀虫剂和杀螨剂。即使其残留量极微，也会对人类和许多动物有害。在本研究中，进行了胶体金颗粒和抗体 - 胶体金偶联物的合成与鉴定，并制备了胶体金免疫层析试纸条用于检测甲胺磷残留。使用透射电子显微镜（TEM）检查胶体金颗粒的大小。通过紫外/可见光谱监测抗体 - 胶体金偶联物的形成。胶体金免疫层析试纸条的制备、甲胺磷标准溶液以及其他四种农药和蔬菜样品的分析均采用常规方法和原理进行操作。TEM图像显示胶体金颗粒的平均直径几乎相同：直径约为40.0nm。对于胶体金与单克隆抗体（MAb）的偶联，已确认0.03mg/ml的MAb是稳定胶体金的最小用量。用制备的胶体金免疫层析试纸条测定甲胺磷标准溶液，结果表明检测限约为1.0mg/ml。交叉反应表明该试纸条对甲胺磷具有高特异性。10个绿色蔬菜样品的检测结果证实，通过高效液相色谱分析有一个样品呈阳性。有证据表明成功合成了胶体金颗粒和抗体 - 胶体金偶联物。所制备的胶体金免疫层析试纸条适用于甲胺磷残留的初步筛查。
