高等学校化学学报 ›› 2012, Vol. 33 ›› Issue (08): 1692.doi: 10.3969/j.issn.0251-0790.2012.08.011

• 分析化学 • 上一篇    下一篇

基于目标物诱导置换及纳米金催化的新型荧光技术检测腺苷

刘雪平1,2, 欧阳湘元1, 吴会旺1, 沈国励1, 俞汝勤1   

  1. 1. 湖南大学化学化工学院, 化学生物传感与化学计量学国家重点实验室, 长沙 410082;
    2. 河南城建学院环境与市政工程系, 平顶山 467036
  • 收稿日期:2011-10-10 出版日期:2012-08-10 发布日期:2012-08-10
  • 通讯作者: 俞汝勤, 男, 教授, 博士生导师, 中国科学院院士, 主要从事化学生物传感与化学计量学研究. E-mail: rqyu@hnu.edu.cn E-mail:rqyu@hnu.cn
  • 基金资助:

    国家自然科学基金(批准号: 21025521, 21035001)和国家"九七三"计划项目(批准号: 2011CB911000)资助.

Novel Fluorescent Technique for Detecting Adenosine Based on DNA Strand Displacement Induced by Target-aptamer Complex and Metal Deposition Catalyzed by Gold Nanoparticles

LIU Xue-Ping1,2, OUYANG Xiang-Yuan1, WU Hui-Wang1, SHEN Guo-Li1, YU Ru-Qin1   

  1. 1. State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan Uinversity, Changsha 410082, China;
    2. Department of Environmental and Municipal Engineering, Henan University of Urban Construction, Pingdingshan 467036, China
  • Received:2011-10-10 Online:2012-08-10 Published:2012-08-10

摘要: 在一定条件下, 磁性纳米颗粒上修饰的腺苷核酸适体与纳米金标记的核酸探针杂交; 再加入目标物腺苷诱导适体构象变换, 并置换出金标探针; 经磁场分离后, 游离的金标探针进一步用于催化抗坏血酸还原铜离子, 使铜离子对钙黄绿素的荧光猝灭得到抑制. 由于极少量的纳米金能够催化大量铜离子还原并沉积在其表面, 铜离子浓度急剧降低, 从而改变钙黄绿素的荧光信号. 实验结果表明, 腺苷的动力学响应浓度范围为100 pmol/L~10 nmol/L, 检出限低至80 pmol/L. 核酸适体的高度特异识别性能保证了该方法具有良好的选择性.

关键词: 纳米金, 催化沉积, 磁性纳米颗粒, 核酸适体, 荧光猝灭抑制

Abstract: Using adenosine as model analyte, a novel homogeneous fluorescent method with high sensitivity and specificity was proposed. It involves two kinds of DNA probe conjugated nanoparticles-aptamer modified magnetic nanoparticles and capture DNA probe derivatized gold nanoparticles(GNPs), which were connected together via hybridization. The conformational transition of aptamer induced by adenosine-aptamer complex contributes to the displacement of probe conjugated GNP, which further catalyzes the reduction of Cu2+ by ascorbic acid, causing the deposition of Cu atom on the surface of GNP. The fluorescence quenching of calcein was restored as the consumption of Cu2+. The experimental results demonstrated that the dynamic range for adenosine detection was from 100 pmol/L to 10 nmol/L, with a detection limit of 80 pmol/L. The proposed method shows high selectivity for the specific recognition of adenosine by its aptamer.

Key words: Gold nanoparticles, Catalytic deposition, Magnetic nanoparticles, Aptamer, Inhibition of fluorescence quenching

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