title: A fluorescence turn-on detection of copper(II) based on the template-dependent click ligation of oligonucleotides.
abstract: In this work, a fluorescence turn-on method for copper(II) detection is reported. A molecular beacon (MB) was designed as a template. Cu(2+) was reduced to Cu(+) in the presence of a reductant (ascorbic acid). Two short single-stranded oligonucleotides one was labeled with a 5'-alkyne and the other with 3'-azide group, proceeded a template-dependent chemical ligation through the Cu(I)-catalyzed azide-alkyne cycloaddition. The newly generated click-ligated long chain oligonucleotide, which was complementary to the MB, opened the MB hairpin structure and resulted in a turn on fluorescence. The increase in fluorescence intensity is directly proportional to the amount of Cu(2+) added to the assay solution. The present assay is quite sensitive and allows the detection of 2 nM Cu(2+). The described assay also exhibits high selectivity over other metal ions.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Wenying
authors.initials: W
authors.lastname: Li
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
authors.forename: Qingfeng
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad 22060, Pakistan.
authors.forename: Sohail
authors.initials: S
authors.lastname: Anjum Shahzad
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China. Electronic address: congyu@ciac.ac.cn.
authors.forename: Cong
authors.initials: C
authors.lastname: Yu
mesh_terms: D000480:Alkynes / Q000737:chemistry; D001205:Ascorbic Acid / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D002413:Cations, Divalent; D057930:Click Chemistry; D003300:Copper / Q000032:analysis*; D061565:Cycloaddition Reaction; D005453:Fluorescence; D006801:Humans; D057230:Limit of Detection; D015335:Molecular Probes / Q000138:chemical synthesis / Q000737:chemistry*; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling / Q000379:methods; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000480:Alkynes; D001386:Azides; D002413:Cations, Divalent; D015335:Molecular Probes; D009841:Oligonucleotides; D014874:Water Pollutants, Chemical; D014867:Water; D003300:Copper; D001205:Ascorbic Acid
keywords: Click chemistry; Copper; Fluorescence; Molecular beacon