Spectral characteristics of the trypaflavine dye in a silica matrix

The mechanism of interaction of molecules of the dye trypaflavine with the surface and the bulk phase of silica gel has been investigated by electron spectroscopy. The character of the optical spectra of trypaflavine in a silica matrix is determined by the method of blending. Molecules of the dye are tied to the silicon dioxide substrate by an ionic bond; protonation of trypaflavine via the side amino groups and the acidic OH groups of the silica gel also takes place. In the simultaneous precipitation of the dye with polysilicic acid the encapsulated molecules possess an anomalously long afterglow, with extinguishment times ranging from tens of nanoseconds to seconds, which is not extinguished by oxygen. The mechanism of the retarded fluorescence of the adsorbed dye is discussed.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 6, pp. 748–753, November–December, 1985.