文献类型：期刊文献

英文题名："Turn-On" Fluorescent Sensor for Hg2+ Based on Single-Stranded DNA Functionalized Mn:CdS/ZnS Quantum Dots and Gold Nanoparticles by Time-Gated Mode

作者：Huang, Dawei[1];Niu, Chenggang[1];Wang, Xiaoyu[1,2];Lv, Xiaoxiao[1];Zeng, Guangming[1]

第一作者：Huang, Dawei

通讯作者：Niu, CG[1]

机构：[1]Hunan Univ, Coll Environm Sci & Engn, Key Lab Environm Biol & Pollut Control, Minist Educ, Changsha 410082, Hunan, Peoples R China;[2]Xinxiang Univ, Coll Chem & Chem Engn, Xinxiang 453003, Peoples R China

第一机构：Hunan Univ, Coll Environm Sci & Engn, Key Lab Environm Biol & Pollut Control, Minist Educ, Changsha 410082, Hunan, Peoples R China

通讯机构：[1]corresponding author), Hunan Univ, Coll Environm Sci & Engn, Key Lab Environm Biol & Pollut Control, Minist Educ, Changsha 410082, Hunan, Peoples R China.

年份：2013

卷号：85

期号：2

起止页码：1164-1170

外文期刊名：ANALYTICAL CHEMISTRY

收录：;EI(收录号：20130415939424);Scopus(收录号：2-s2.0-84872593757);WOS:【SCI-EXPANDED(收录号:WOS:000313668400071)】；

基金：Special thanks are given to Mr. Y. Charles Cao and his group of the University of Florida for kind assistance in synthesis of Mn-doped CdS/ZnS core/shell QDs. This work was financially supported by the National Natural Science Foundation of China (20977026), the National 863 High Technology Research Foundation of China (2006AA06Z407), the Research Fund for the Doctoral Program of Higher Education of China (20090161110009), the project sponsored by SRF for ROCS, SEM (521294018), and the Fundamental Research Funds for the Central Universities of Hunan University (531107040375).

语种：英文

外文关键词：Cadmium sulfide - CdS nanoparticles - DNA - Fiber optic sensors - Fluorophores - Gold nanoparticles - II-VI semiconductors - Manganese removal (water treatment) - Metal ions - Metal nanoparticles - Metals - Nanocrystals - Semiconductor quantum dots

摘要：An ultrasensitive "turn-on" fluorescent sensor was presented for determination of Hg2+. This method is mainly based on Hg2+-induced conformational change of a thymine-rich single-stranded DNA. The water-soluble long-lifetime fluorescence quantum dot (Mn:CdS/ZnS) acted as the fluorophore, which was labeled on a 33-mer thymine-rich single-stranded DNA (strand A). The gold nanoparticles (GNPs) functionalized 10-mer single-stranded DNA (strand B) is selected as the quencher to quench the fluorescence of Mn:CdS/ZnS. Without Hg2+ in the sample solution, strands A and B could form hybrid structures, resulting in the fluorescence of Mn:CdS/ZnS being decreased sharply. When Hg2+ is present in the sample solution, Hg2+-mediated base pairs induced the folding of strand A into a hairpin structure, leading to the release of GNPs-tagged strand B from the hybrid structures. The fluorescence signal is then increased obviously compared with that without Hg2+. The sensor exhibits two linear response ranges between fluorescence intensity and Hg2+ concentration. Meanwhile, a detection limit of 0.18 nM is estimated based on 3 alpha/slope. Selectivity experiments reveal that the fluorescent sensor is specific for Hg2+ even with interference by high concentrations of other metal ions. This sensor is successfully applied to determination of Hg2+ in tap water and lake water samples. This sensor offers additional advantage to efficiently reduce background noise using long-lifetime fluorescence quantum dots by a time-gated mode. With excellent sensitivity and selectivity, this sensor is potentially suitable for monitoring of Hg2+ in environmental applications.