摘要
以碳二亚胺法合成了对目标植物多肽激素具有高特异性、强亲和作用的适配体功能化磁性纳米量子点荧光探针(Fe3O4@mSiO_2-QDs-Apt),研究了其选择性和荧光特性。首先在Fe3O4磁性纳米粒子上包裹一层二氧化硅以克服Fe3O4磁性纳米粒子自身表现出的不稳定性、易团聚以及被缓慢化学腐蚀等缺点。通过自组装、静电作用、共价作用实现Fe3O4@mSiO_2表面修饰氨基,再以碳二亚胺法偶联上量子点和系统素适配体。通过对体系中缓冲液及其p H值等条件的优化,Fe3O4@mSiO_2-QDs-Apt在p H 8.6的Tris-HCl缓冲液体系中荧光最强,并能与目标系统素多肽特异性结合,使探针的荧光发生猝灭,猝灭程度随加入目标多肽浓度的增大而增强,且Fe3O4@mSiO_2-QDs-Apt探针对不同多肽的识别能力不同。与适配体功能化量子点荧光探针(QDs-Apt)相比较,Fe3O4@mSiO_2-QDs-Apt的荧光强度有所降低,但适配体的特异性识别能力不变,由此拓展了QDs-Apt在生物样品分析中的应用研究。
Aptamer-functionalized magnetic quantum dots（ Fe3O4@ mSiO2-QDs-Apt） with high specificity and affinity for the recognition of target systemin polypeptide hormones were prepared through carbodiimide coupling method,and its recognition and fluorescence properties were investigated in this work. First,magnetic iron oxide nanoparticles were packed by silicon dioxide in order to overcome their disadvantage of Fe3O4 magnetic nanoparticles,then systemin aptamer-functionalized quantum dots were bound on the carboxyl modification Fe3O4@mSiO2 surface by carbodiimide coupling method. The fluorescence properties of the prepared Fe3O4@ mSiO2-QDs-Apt were investigated by optimizing experimental conditions,including buffer,p H value and recognition time. The results show that the fluorescence intensity of Fe3O4@ mSiO2-QDs-Apt was strongest in the Tris-HCl buffer system at pH 8. 6,at the same time they were stable in the selected buffer system. The fluorescence intensity of Fe3O4@ mSiO2-QDs-Apt was lower than that of QDs-Apt,but the recognition ability was similar between them,which may help the applications of aptamer-functionalized quantum dots in bioanalysis.
出处
《桂林理工大学学报》
CAS
北大核心
2016年第2期326-332,共7页
Journal of Guilin University of Technology
基金
国家自然科学基金项目(21265004
21465008)
广西自然科学基金项目(2014GXNSFAA118063)
广西教育厅科研项目(201203YB086)
关键词
适配体
量子点
系统素
多肽激素
磁性纳米粒子
荧光探针
aptamer
quantum dots
systemin
polypeptide hormones
magnetic nanoparticles
fluorescence probe
