Application of laser confocal fluorescence spectroscopy in studies of spatial distribution of porphyrin molecules on plasma deposited polymer films

Abstract

Laser confocal microscopy combined with spatially-resolved fluorescence spectroscopy were used for the analysis of surface distribution and state of di(p-aminophenyl)etioporphyrin (DAPEP) and tetra(p-aminophenyl)porphyrin (TAPP) molecules deposited on thin (7 – 15 μm) treated by 0.5 M KCl solution and activated by air non-equilibrium plasma at the normal atmospheric pressure. Confocal microscopy data show that after treatment the polymer surface becomes inhomogeneous, and porphyrin moieties are randomly distributed on both film surfaces with a penetration depth of ∼1 µm. On the basis of spatially resolved fluorescence measurements it has been found that fluorescence spectra of individual spots correspond to monomeric species. It means that spatially closed few porphyrin molecules in the spot are not aggregated and do not interact significantly