水溶性ZnSe量子点在快速灵敏检测牛分枝杆菌表面MPB83蛋白中的应用

Application of Water-soluble ZnSe Quantum Dots on Rapid and Sensitive Detection of MPB83 Protein on Surface of Mycobacterium Bovis

本实验以巯基丙酸作为稳定剂,在水相条件下快速合成稳定性好的水溶性硒化锌量子点（ ZnSe QDs）,采用透射电子显微镜、X射线衍射、红外光谱、荧光以及紫外光谱法等对ZnSe QDs进行了材料表征。将得到的ZnSe QDs通过共价结合方式标记到牛分枝杆菌表面的MPB83蛋白抗体分子上,基于抗体与MPB83蛋白的特异性相互作用,建立了一种检测MPB83蛋白的光谱新方法。研究了pH值及温度对检测的影响,得到pH 8.5,37℃为适宜的体系酸度和温度。在优化的实验条件下,MPB83蛋白浓度在44~528 mg/L范围内,QDs的荧光强度与蛋白浓度间呈现良好的线性关系,此方法对MPB83蛋白的检出限为4.4 mg/L。该方法为实现准确而及时的诊断牛结核病提供一定理论依据。

A basic water phase method was used for synthesizing water-soluble ZnSe quantum dots （ QDs ） with 3-mercaptopropionic acid （ MPA ） as ligands. The obtained MPA-ZnSe QDs were characterized by transmission electron microscopy, X-ray powder diffraction spectrometry, ultraviolet-visible spectrometry and fluorescence spectrometry. Then the prepared MPA-ZnSe QDs were conjugated with anti-MPB83 antibodies to form the fluorescent probe. As a result of specific interaction, MPB83 proteins were selectively captured by immunized MPA-ZnSe QDs which led to the change of a fluorescent signal. Based on this, a fluorescence-linked immunoassay method was demonstrated for the detection of MPB83 proteins. The influence of pH and temperature were studied, thus the optimum reaction condition （ pH 8. 5, 37 ℃） were obtained. Under optimal conditions, the quenched fluorescence intensity increased linearly with the concentration of MPB83 proteins ranging from 44 to 528 mg/L with the detection limit of 4. 4 mg/L. The approach provides theoretical basis for diagnosing bovine tuberculosis precisely and timely.