分析化学2024，Vol.52Issue(5)：674-684,中插10-中插13,15.DOI:10.19756/j.issn.0253-3820.231159
荧光探针置换型核酸适配体传感器检测生物小分子
Aptasensor for Detection of Small Molecules Based on Displacement Fluorescent Probe
摘要
Abstract
By using thioflavin T(ThT)as displacement-based fluorescent probes,three kinds of aptasensors were constructed for rapid detection of three kinds of small molecules such as ochratoxin A(OTA),aflatoxin B1(AFB1)and adenosine.In the absence of target molecule,ThT bound with the aptamer to form an aptamer-ThT complex and exhibited a significant fluorescence response.Upon the addition of target molecule,because of the higher affinity between target and aptamer than that between ThT and the aptamer,ThT was displaced by the target molecule from the aptamer-ThT complex,resulting in weakened fluorescence signal.Based on this principle,the target molecule could be detected quantitatively.Further study through circular dichroism spectra showed that there was no significant change in the conformation of the aptamer after addition of ThT or target molecules.The stoichiometric ratios of ThT to OTAapt,AFB1apt and Adeapt measured through the method of equimolar continuous variation was 1∶1,1∶1 and 2∶1,respectively,and their dissociation constants were all larger than those between the target molecule and its aptamer.Therefore,the principle of this detection method was the displacement of fluorescent probe(ThT)in aptamer-ThT complex by target molecule,resulting in decrease of fluorescence intensity.Under optimal experimental conditions,the limits of detection(LODs)were 0.8 nmol/L for OTA,1.3 nmol/L for AFB1,and 0.10 μmol/L for adenosine,respectively.This method was label-free,simple to operate,with low cost,good selectivity and high sensitivity.The developed assay kit based on this method could be used for actual sample detection.关键词
核酸适配体传感器/置换型荧光探针/硫磺素T/赭曲霉毒素A/黄曲霉毒素B1/腺苷Key words
Aptasensor/Displacement fluorescent probe/Thioflavin T/Ochratoxin A/Aflatoxin B1/Adenosine引用本文复制引用
杨成,崔胜楠,王越,王国峰,李程铭,谷双超,薛长颖..荧光探针置换型核酸适配体传感器检测生物小分子[J].分析化学,2024,52(5):674-684,中插10-中插13,15.基金项目
国家自然科学基金项目(No.21876017)、中央高校基本科研业务费专项资金项目(Nos.DUT22YG120,DUT21LAB130,DUT17LAB18)、电分析化学国家重点实验室开放课题项目(No.SKLEAC202105)、农业部生物毒素检测重点实验室开放课题(No.201702)和大连理工大学大学生创新训练项目(No.20221014110489)资助. Supported by the National Natural Science Foundation of China(No.21876017),the Fundamental Research Funds for the Central Universities(Nos.DUT22YG120,DUT21LAB130,DUT17LAB18),the Open Funds of State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC202105),the Open Funds of Key Laboratory of Detection for Mycotoxins,Ministry of Agriculture(No.201702)and the Student's Platform for Innovation and Entrepreneurship Training Program(No.20221014110489). （No.21876017）
