荧光核酸适配体功能化氧化石墨烯生物传感器用于快速检测氯霉素  

Fluorescent Aptamer-functionalized Graphene Oxide Biosensor for Rapid Detection of Chloramphenicol

作　　者：卢静荷 谭淑珍[1] 朱雨清 李伟[1] 陈天啸 王瑶 刘陈[1] Lu Jinghe;Tan Shuzhen;Zhu Yuqing;Li Wei;Chen Tianxiao;Wang Yao;Liu Chen(School of Chemical and Biological Engineering, Changsha University of Science and Technology, Changsha 410114)

机构地区：[1]长沙理工大学化学与生物工程学院

出　　处：《化学学报》2019年第3期253-256,共4页Acta Chimica Sinica

基　　金：湖南省教育厅科研基金(No.17C0033)资助~~

摘　　要：开发了一种无标记和快速的检测方法基于氧化石墨烯(GO)和荧光功能性G-四聚体探针(FGP),可用于定量检测氯霉素(CAP).FGP由氯霉素核酸适配体和富含G碱基的核酸序列组成.核酸适配体用于结合CAP,并且由富含G碱基的核酸序列在K+,Na+离子的作用下形成的G-四聚体,然后与硫磺素T(ThT)结合后用作信号分子.在没有CAP的情况下,FGP通过π-π堆积相互作用被吸附到GO的表面上,阻碍了G-四聚体的形成导致溶液中的荧光强度低.在加入CAP时,FGP的核酸适配体部分可识别并结合CAP以形成复合物,导致其从GO解吸.因此,游离的富含G的碱基序列可以形成G-四聚体结构并与ThT结合,导致溶液的荧光强度增加.我们观察到荧光强度增加与CAP浓度在2~20 nmol/L范围内呈线性关系,检测限为1.45 nmol/L.此外,该检测系统用于检测加标牛奶中的CAP,回收率在93.2%~103.3%之间.这些结果表明,开发的方法可用于有效检测实际样品中的CAP.A label free and rapid fluorescent method for quantitative detection of chloramphenicol (CAP) based on graphene oxide (GO) fluorescence functional G-quadruplex probe (FGP) was developed. The FGP consisted of a choramphenicol aptamer and a G-rich sequence. The aptamer was used to bind CAP and the G-quadruplex formed by G-rich sequence was employed as a signal reporter after binding to Thioflavin T (ThT). In the absence of CAP, the FGP was absorbed onto the surface of GO through π-π stacking interactions, which restrained the G-rich sequence to form a G-quadruplex structure. Thus, the fluorescent intensity of background was low. In the addition of the CAP, the aptamer part of FGP could recognize and bind CAP to form a target-FGP complex, which led to the desorption of the complex from GO. Therefore, the free G-rich sequence could form G-quadruplex structure and bind to ThT, resulting a increase in the fluorescence intensity of the solution. We observed that the fluorescence increasement of the sensing platform had a linear relationship with the concentrations of CAP in the range of 2~20 nmol/L, and the limit of detection was 1.45 nmol/L. Besides, this detection system was applied for detecting CAP in the spiked milk, the recovery rate was between 93.2%~103.3%. These results indicated that this developed method can be used to efficiently recognize CAP in real samples.

关 键 词：核酸适配体 荧光 氯霉素 G-四聚体 氧化石墨烯 

分 类 号：O657.3[理学—分析化学]