摘要
稀土离子(Er^(3+))可与荧光石墨烯量子点(GQDs)表面的含氧基团发生配位,在Er^(3+)介导下形成高配位数的GQDs/Er^(3+)配合物,引起GQDs聚集而使其荧光减弱。凝血酶(Tb)中的氮和氧等原子可与Er^(3+)发生配位作用,从而与GQDs竞争结合Er^(3+),减弱了GQDs与Er^(3+)的作用而使其荧光恢复。通过检测GQDs的荧光即可实现对Tb活性的高灵敏分析,构建了基于Er^(3+)介导GQDs荧光开关的Tb传感方法,采用透射电镜、原子力显微镜、红外吸收光谱以及荧光光谱等对传感机理进行了研究。本方法对Tb的检出限低至0.049 nmol/L,其它蛋白质对Tb检测无明显干扰,实际样品中Tb加标回收率为98.0%~105.3%,相对标准偏差为0.6%~4.2%。
A label-free method for sensitive and selective detection of thrombin( Tb) was constructed based on rare earth ion mediated fluorescence switch of graphene quantum dots( GQDs). Rare earth ion( Er^(3+)) can assemble onto the surface of GQDs through the coordination interaction between Er^(3+)ions and the carboxylate groups located on the surface or edge of the GQDs,resulting in the aggregation of the GQDs and thereby decrease of the fluorescence of the GQDs. In the presence of Tb,the oxygen and nitrogen-donor atoms in Tb can coordinate with Er^(3+)ions and compete with the carboxylate groups on GQDs to coordinate Er^(3+)ions,thus the interaction between GQDs and Er^(3+)ions is reduced, which lead to the restoration of the GQDs fluorescence. In this study,the sensing mechanism was demonstrated by transmission electron microscopy,atomic force microscope, Fourier transform infrared spectroscopy, UV-Vis absorption and fluorescence spectroscopy. The limit of detection for Tb assay was as low as 0. 049 nmol/L. Moreover,this assay was successfully applied to the selective determination of Tb in real samples.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2017年第12期1915-1920,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金项目(Nos.21475056
21675078)
江西省主要学科学术带头人培养对象计划项目(Nos.20123BCB22003
20162BCB22013)资助~~
关键词
稀土离子
石墨烯量子点
荧光开关
凝血酶
传感
Rare earth ion
Graphene quantum dots
Fluorescence switch
Thrombin
Sensing
