利用微悬臂梁传感对瘦肉精进行非标记检测

Label-free detection of clenbuterol based on microcantilever

目的利用微悬臂梁传感技术对瘦肉精抗原抗体的特异性结合进行检测。方法将巯基化的瘦肉精抗体通过自组装修饰到微悬臂梁的金面,在加入不同浓度的瘦肉精标准样品的过程中,通过光杠杆原理监测微悬臂梁的实时弯曲信号。巯基化瘦肉精抗体的活性和微悬臂梁上抗原抗体的结合得到酶联免疫吸附(ELISA)实验的验证。结果该系统能够检测至少1μg/L浓度的瘦肉精标准样品,而且具有很强的选择性,在对照实验中加入不含瘦肉精的1 mg/L氯霉素溶液没有响应。另外,瘦肉精抗原抗体的结合导致微悬臂梁产生压应力,而且微悬臂梁表面应力的改变与样品浓度的对数成线性关系。结论利用微悬臂梁传感技术对瘦肉精的检测是可行的。

Objective A novel technology of microcantllever sensor platform for label-free detection of clenbuterol antigen-antibody specificity binding is reported. Method Thiolated clenbuterol antibody was immobilized on the gold-coated side of the microcantilever by self-assem bled m onolayer technique. Consequently the deflections of the microcantilever corresponding to the process of injecting different concentration of clenbuterol antigen were real-time monitored by optical lever technique. The activity of thiolated clenbuterol antibody and the clenbuterol antigen-antibody binding on the gold-coated side of the microcantilever were confirmed by an Enzyme-Linked Immunosorbent Assay （ELISA）. Result The sensitivity of detecting clenbuterol is better than 1 μg/L. Microcantilevers functionalized with thiolated clenbuterol antibodies were exposed to 1 mg/L of Chloramphenicol （CAP）, and no significant response was detected, which confirmed the specificity of the immobilization method. In addition, clenbuterol antigen-antibody binding on the microcantilever generates a compressive surface stress and the surface stress is linear to logarithm of clenbuterol concentration over a range of concentration from 1 ng/mL to 1 μg/mL. Conclusions It is possible for detection of clenbuterol by microcantilever sensor platform.