Fluorescence sensitization of gold-glutathione nanoclusters by aqueous solutions of sodium and potassium ions
Fluorescence sensitization of gold-glutathione nanoclusters by aqueous solutions of sodium and potassium ions
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DOI：
10.1007/s00604-015-1475-y
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发表时间：
2015-04
影响因子：
5.7
通讯作者：
M. Francos;R. Badía-Laíño;M. E. Díaz-García
中科院分区：
文献类型：
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作者：
M. Francos;R. Badía-Laíño;M. E. Díaz-García
金纳米团簇（Au-NC）是用于荧光测定和成像的常用染料的有力替代品。这是由于它们的高亮度和生物相容性。使用谷胱甘肽保护的金纳米团簇（Au-NCs@GSH）来研究钠和钾离子（在0.1至ImM浓度下）对其荧光的影响。发现这些碱金属离子的添加不改变AuNCs@GSH的发射波长，但荧光强度经历逐渐增加（约130%）直到达到平台。KSCN特别增强荧光。该效应被解释为取决于阴离子的性质的AuNCs@GSH的带隙的减小。结果说明了缓冲液中常用的阴离子和一价阳离子对AuNCs@GSH的荧光调节的作用。当在基于荧光增强或淬灭的测定中使用AuNCs@GSH时，应考虑这些发现。图示摘要一价金属离子（Na+，K+）通过簇间桥接诱导谷胱甘肽保护的金簇聚集。桥接的金属聚集体表现出增强的荧光发射，缓和的阳离子结合常数和两者，长寿命的寿命组件和对离子敏感的能带隙。
Gold nanoclusters (Au-NCs) are powerful alternatives to commonly used dyes for use in fluorescent assays and in imaging. This is due to their high brightness and biocompatibility. Glutathione protected gold nanoclusters (Au-NCs@GSH) were used to investigate the effect of sodium and potassium ions (at 0.1 to 1 mM concentrations) on their fluorescence. It was found that addition of these alkali ions does not modify the emission wavelength of AuNCs@GSH, but fluorescence intensity undergoes a gradual increase (by ~130 %) until a plateau is reached. Fluorescence is particularly enhanced by KSCN. The effect is interpreted in terms of a decrease in the band gap of the AuNCs@GSH that depends on the nature of the anion. The results illustrate the role of anions and monovalent cations commonly used in buffers with respect to the tuning of the fluorescence of AuNCs@GSH. The findings should be taken into account when using AuNCs@GSH in assays based on fluorescence enhancement or quenching.Graphical AbstractMonovalent metal ions (Na+, K+) induce the aggregation of glutathione-protected gold clusters via inter-cluster bridging. The bridged metal aggregates exhibit enhanced fluorescence emission, moderated cation binding constants and both, a long-lived lifetime component and an energy band-gap sensitive to the ions.