title: Characterization and application to the detection of single-stranded DNA binding protein of fluorescent DNA-templated copper/silver nanoclusters.
abstract: A simple strategy for the preparation of strongly fluorescent and stable DNA-Cu/Ag NCs from reduction of AgNO(3) and Cu(NO(3))(2) by NaBH(4) in the presence of DNA having a sequence 5'-CCCTTAATCCCC-3' has been demonstrated. Fluorescence, absorption, X-ray photoelectron spectroscopy (XPS), and electrospray ionization-mass spectrometry (ESI-MS) measurements have been applied to the characterization of the DNA-Cu/Ag NCs. The ESI-MS data reveal that each DNA-Cu/Ag NC contained 2 Ag and 1 Cu atoms. The interactions among DNA with the Ag and Cu atoms are further supported by the data of low-temperature fluorescence. In the presence of Cu(2+) ions, the reaction time is 1.5 h, which is much shorter than that (120 h) for the preparation of Ag-DNA NCs that are prepared in a mixture of AgNO(3), NaBH(4) and DNA without containing Cu(2+) ions. Relative to the DNA-Ag NCs, the DNA-Cu/Ag NCs have greater fluorescence (quantum yield 51.2% vs. 11.5%). The DNA-Cu/Ag NCs are highly sensitive and selective for the detection of single-stranded DNA binding protein (SSB), with a linear range 1-50 nM and a limit of detection 0.2 nM at a signal-to-ratio of 3.
authors.affiliation: Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan.
authors.forename: Guo-Yu
authors.initials: GY
authors.lastname: Lan
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Chen
authors.forename: Huan-Tsung
authors.initials: HT
authors.lastname: Chang
mesh_terms: D003300:Copper / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000032:analysis*; D005456:Fluorescent Dyes / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011485:Protein Binding; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D005456:Fluorescent Dyes; D012834:Silver; D003300:Copper