Fluorescence of cyanine dye excimers in nanoporous silica

Abstract

Adsorption of cyanine dye DiI in a nanopous SiO₂ matrix has been studied. It was shown that the increase of the dye concentration in the SiO₂ matrix provokes the appearance of an additional red-shifted band of excimer nature in the dye fluorescence spectrum without any changes in the absorption one. Static character of the dye excimer formation was revealed. Enhanced dye concentration due to spatial confinement in a nanopore volume has been supposed as a reason of the effective excimer formation.