Center for Self-Assembly and Complexity, Institute for Basic Science, and Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
Department of Chemistry, Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea.
Biosens Bioelectron. 2015 Jun 15;68:642-647. doi: 10.1016/j.bios.2015.01.058. Epub 2015 Jan 28.
A fluorescence switch that consists of DNA-templated silver nanoclusters (DNA-AgNCs) triggered by silver ion (Ag(+)) is developed to detect Ag(+). The mechanism of the fluorescence switching of DNA-AgNCs is investigated by fluorescence spectroscopy, circular dichroism spectroscopy, DNA hybridization assay and mass spectrometry. Ag(+) induces a dimeric structure of Cyt12-AgNCs by forming a bridge between two Cyt12-AgNCs, where Cyt12 is cytosine 12-mer; this dimer formation causes the fluorescence change of Cyt12-AgNCs from red to green. Using this Ag(+)-triggered fluorescence switch, we successfully detected Ag(+) at concentrations as low as 10nM. Furthermore, we quantitatively detected the Ag(+) in the Silmazin(®), which is dermatological burn ointment having silver sulfadiazine. Ag(+) detection using this fluorescence switch has high selectivity and sensitivity, and short response time, and can be used successfully even in the presence of other metal ions.
一种由 DNA 模板银纳米簇（DNA-AgNCs）组成的荧光开关，由银离子（Ag(+))触发，用于检测 Ag(+)。通过荧光光谱、圆二色光谱、DNA 杂交分析和质谱研究了 DNA-AgNCs 的荧光开关机制。Ag(+)通过在两个 Cyt12-AgNCs 之间形成桥，诱导 Cyt12-AgNCs 形成二聚体结构，其中 Cyt12 是 12 个碱基的胞嘧啶；这种二聚体形成导致 Cyt12-AgNCs 的荧光从红色变为绿色。使用这种 Ag(+)-触发的荧光开关，我们成功地在低至 10nM 的浓度下检测到 Ag(+)。此外，我们还定量检测了含有磺胺嘧啶银的 Silmazin(®)（一种皮肤科烧伤软膏）中的 Ag(+)。这种荧光开关具有高选择性和灵敏度，响应时间短，即使存在其他金属离子也能成功使用。
