应用纳米与分子探针技术对IgG抗原水平的检测  

Detection of the Antigen IgG Microconcentration with Nanotechnology and Molecular Probes Technology

作　　者：周波[1] 王海燕[1] 楼莎[1] 刘珍宝[1] 朱敦皖[1] 冷希岗[1] 

机构地区：[1]中国医学科学院.中国协和医科大学生物医学工程研究所,天津300192

出　　处：《科技导报》2009年第22期38-43,共6页Science & Technology Review

基　　金：科技部社会公益项目(2005DIB1J094)

摘　　要：人们研究并逐步认识了纳米金与DNA等相互作用的特性和条件,并对以纳米金为基础发展起来的生物条码技术进行了更加深入的研究与应用。基于纳米金的生物条码及其相关技术研究与应用日益广泛,并不断有创新,本研究应用纳米技术并结合分子探针技术对低浓度的抗原水平进行检测。该生物条码技术常被用于检测某些蛋白、核酸、细胞或细胞因子的水平,并由此形成了不同于PCR、ELISA但仍具有高灵敏度特性的检测方法。通过磁性微球标记单抗以捕获、富集待测抗原,修饰多抗与亲和素的纳米金并结合分子信标探针起到信号扩增的作用。通过二硫键(—S—S—)分子信标探针茎部3’端的碱基T连接一生物素分子。待测抗原可将磁球与纳米金系统进行连接,然后应用二硫苏糖醇(DTT)将连接于纳米金上的MB切割下来,并与其环部完全互补配对的靶序列杂交后测定荧光强度。荧光强度与待测抗原水平(含量)相关。With better understanding of the characteristics and conditions of the interaction between the gold nanopartieles and DNA, people are developing the bio-bar-code growth technology based on the gold nanoparticles. The method is widely applied te detect the level or mieroconcentration of some proteins, nucleic acid, cells and cytokines. New methods are confing into being with higher sensitivity as distinct from the PCR and ELISA. The bio bar-code and the related technology based upon the gold nanoparticles are being continuously innovated. In this paper, the microconcentration of the antigen IgG is detected by applying nanotechnology and molecular probes technology in the experiment. The magnetic microbeads modified with the monocolon antibody are used to capture the target antigen IgG, to modify the gold nanoparticles with the polycolonal antibody and the avidin combined with the molecular beacons, thus to modify the biotin through the disulfide bonds at the T base position of the 3 terminal of the stem, and to amplify the signal in cascades. The magnetic microbeads can be combined with the gold nanoparticles through the detected antigen IgG. Then the DTF could cut the MB off the gold nanoparticles through the reduction effect and the free MB can be hybridized with its target sequence. Then the fluorescence density is measured with Spectrofluorometer. The results show that there are some relationships between the fluorescence density and the concentration of the antigen IgG. The detection sensitivity of the research is very high, which reaches 1pg/ml, about the 6.67 fM.

关 键 词：纳米技术 分子探针 磁性微球 纳米金 分子信标 IgG抗原 亲和素 生物素 

分 类 号：Q503[生物学—生物化学]