Siejak Przemysław, Frackowiak Danuta
Institute of Physics, Poznań University of Technology, Nieszawska 13A, 60-965 Poznań, Poland.
J Phys Chem B. 2005 Aug 4;109(30):14382-6. doi: 10.1021/jp058058t.
The absorption, fluorescence excitation, and fluorescence emission spectra of water solutions of fluorescein dye with the addition of various amounts of a colloidal silver suspension have been measured in order to check if in such systems it is possible to distinguish the change in photonic mode density due to the metal presence from the other effects such as the influences of the microemulsion system on the spectral properties of the dye. It has been found that the presence of the silver colloid changes the concentrations of the various ionic forms of fluorescein, characterized by different yields of fluorescence. This effect is partially responsible for the change in the yield of the fluorescence emission observed at certain concentrations of the dye and the colloids. But even at the same concentration of various ionic forms of fluorescein (at the same pH of the dye solution and the dye-colloid mixture), at certain concentrations of fluorescein and the colloid, the yield of the dye fluorescence increases, which must be due to the interaction between the dye and the silver colloid. Because of the superposition of several processes influencing the dye yield of fluorescence, it is necessary to carefully establish the properties of the dye in a given environment, before considering its practical application as a marker of the metal presence. It is not excluded that similar complex effects could also occur in biological samples containing natural pigments and colloids of metals. Investigations of other dyes with other forms of metallic samples are in progress.
为了检验在这样的体系中是否有可能将由于金属存在导致的光子模式密度变化与其他效应（如微乳液体系对染料光谱性质的影响）区分开来，我们测量了添加不同量胶体银悬浮液的荧光素染料水溶液的吸收光谱、荧光激发光谱和荧光发射光谱。已经发现银胶体的存在改变了荧光素各种离子形式的浓度，这些离子形式具有不同的荧光产率。这种效应部分地导致了在染料和胶体的某些浓度下观察到的荧光发射产率的变化。但是，即使在荧光素各种离子形式浓度相同的情况下（在染料溶液和染料 - 胶体混合物的相同pH值下），在荧光素和胶体的某些浓度下，染料荧光产率仍会增加，这必定是由于染料与银胶体之间的相互作用。由于影响染料荧光产率的几个过程相互叠加，在考虑将其实际用作金属存在的标记物之前，有必要仔细确定染料在给定环境中的性质。不排除在含有天然色素和金属胶体的生物样品中也可能出现类似的复杂效应。对其他具有其他形式金属样品的染料的研究正在进行中。
