title: Sensitive detection of mercury and copper ions by fluorescent DNA/Ag nanoclusters in guanine-rich DNA hybridization.
abstract: In this work, we designed a new fluorescent oligonucleotides-stabilized silver nanoclusters (DNA/AgNCs) probe for sensitive detection of mercury and copper ions. This probe contains two tailored DNA sequence. One is a signal probe contains a cytosine-rich sequence template for AgNCs synthesis and link sequence at both ends. The other is a guanine-rich sequence for signal enhancement and link sequence complementary to the link sequence of the signal probe. After hybridization, the fluorescence of hybridized double-strand DNA/AgNCs is 200-fold enhanced based on the fluorescence enhancement effect of DNA/AgNCs in proximity of guanine-rich DNA sequence. The double-strand DNA/AgNCs probe is brighter and stable than that of single-strand DNA/AgNCs, and more importantly, can be used as novel fluorescent probes for detecting mercury and copper ions. Mercury and copper ions in the range of 6.0-160.0 and 6-240 nM, can be linearly detected with the detection limits of 2.1 and 3.4 nM, respectively. Our results indicated that the analytical parameters of the method for mercury and copper ions detection are much better than which using a single-strand DNA/AgNCs.
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Peng
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China. Electronic address: lingjian@ynu.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Ling
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
authors.forename: Xiu-Qing
authors.initials: XQ
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Bai
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China. Electronic address: qecao@ynu.edu.cn.
authors.forename: Qiu-E
authors.initials: QE
authors.lastname: Cao
authors.affiliation: Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China.
authors.forename: Zhong-Tao
authors.initials: ZT
authors.lastname: Ding
mesh_terms: D001483:Base Sequence; D002413:Cations, Divalent / Q000032:analysis; D003300:Copper / Q000032:analysis*; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006147:Guanine / Q000737:chemistry; D057230:Limit of Detection; D008628:Mercury / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D002413:Cations, Divalent; D005456:Fluorescent Dyes; D012834:Silver; D006147:Guanine; D003300:Copper; D004247:DNA; D008628:Mercury
keywords: Copper; DNA/Ag nanoclusters; Fluorescence; Guanine-enhanced; Mercury