通过在巯基丙酸存在下恢复 DNA 模板化的铜/银纳米团簇的荧光来检测铜离子。

Detection of copper ions through recovery of the fluorescence of DNA-templated copper/silver nanoclusters in the presence of mercaptopropionic acid.

机构信息

Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan.

出版信息

Anal Chem. 2010 Oct 15;82(20):8566-72. doi: 10.1021/ac101659d.

PMID:20873802

Abstract

We have developed a simple and homogeneous fluorescence assay, comprised of 3-mercaptopropionic acid (MPA) and DNA-Cu/Ag nanoclusters (NCs) in aqueous solution, for the detection of Cu(2+) ions. The fluorescence of the DNA-Cu/Ag NCs was quenched by MPA, which was recovered in the presence of Cu(2+) ions. This MPA-induced fluorescence quenching arises through changes in the DNA conformation that occur after interactions between MPA and the Cu/Ag clusters. The MPA-induced fluorescence quenching displayed typical characteristics in Stern-Volmer plots; it followed a static quenching mechanism. The presence of Cu(2+) ions resulted in the oxidation of MPA to form a disulfide compound, leading to recovery of the fluorescence of the DNA-Cu/Ag NCs. The fluorescence of the DNA-Cu/Ag NCs in the presence of MPA increased upon increasing the concentration of Cu(2+) ions over the range from 5 to 200 nM. The DNA-Cu/Ag NC probe provided the limit of detection (at a signal-to-noise ratio of 3) for Cu(2+) ions of 2.7 nM, with high selectivity (by at least 2300-fold over other tested metal ions). We validated the practicality of using this probe for the detection of Cu(2+) ions in environmental samples through analyses of Montana soil and pond water samples.

摘要

我们开发了一种简单均一的荧光分析法，由 3-巯基丙酸（MPA）和 DNA-Cu/Ag 纳米团簇（NCs）在水溶液中组成，用于检测 Cu(2+)离子。MPA 猝灭了 DNA-Cu/Ag NCs 的荧光，而在 Cu(2+)离子存在的情况下，荧光得到恢复。这种 MPA 诱导的荧光猝灭源于 MPA 与 Cu/Ag 簇相互作用后 DNA 构象的变化。MPA 诱导的荧光猝灭在 Stern-Volmer 图中表现出典型特征；它遵循静态猝灭机制。Cu(2+)离子的存在导致 MPA 被氧化形成二硫化合物，从而恢复 DNA-Cu/Ag NCs 的荧光。在 MPA 存在下，DNA-Cu/Ag NCs 的荧光随着 Cu(2+)离子浓度从 5 到 200 nM 的增加而增加。该 DNA-Cu/Ag NC 探针提供了 Cu(2+)离子的检测限（信噪比为 3）为 2.7 nM，具有高选择性（相对于其他测试的金属离子至少高出 2300 倍）。我们通过对蒙大拿州土壤和池塘水样的分析，验证了该探针用于检测环境样品中 Cu(2+)离子的实用性。