| Abstract
| - The absorption, fluorescence excitation, and fluorescence emission spectra of water solutions of fluoresceindye with the addition of various amounts of a colloidal silver suspension have been measured in order tocheck if in such systems it is possible to distinguish the change in photonic mode density due to the metalpresence from the other effects such as the influences of the microemulsion system on the spectral propertiesof the dye. It has been found that the presence of the silver colloid changes the concentrations of the variousionic forms of fluorescein, characterized by different yields of fluorescence. This effect is partially responsiblefor the change in the yield of the fluorescence emission observed at certain concentrations of the dye and thecolloids. But even at the same concentration of various ionic forms of fluorescein (at the same pH of the dyesolution and the dye−colloid mixture), at certain concentrations of fluorescein and the colloid, the yield ofthe 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 tocarefully establish the properties of the dye in a given environment, before considering its practical applicationas a marker of the metal presence. It is not excluded that similar complex effects could also occur in biologicalsamples containing natural pigments and colloids of metals. Investigations of other dyes with other forms ofmetallic samples are in progress.
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