Spectral properties of stilbazolium merocyanines – potential sensitizers in photodynamic therapy and diagnosis

Photochemical Activity of Merocyanine Dyes

“…1) of the investigated Mero dyes (synthesized by Dr. I. Gruda from Université du Québec, Trois-Rivières, Canada) and the methods of sample preparations and of dye introduction into lymphocytes were described earlier [6,7,9]. The Mero dyes and diazobicyclooctane (DABCO from Sigma) were dissolved in methanol (MeOH) or ethanol (EtOH) (from POCH, Lublin, Poland).…”

“…Applying the method proposed by Small et al [10], the deconvolution of timeresolved photothermal signals for Mero dyes in model systems [6,7], obtained by means of the laser-induced optoacoustic spectroscopy (LIOAS) [11] technique, was performed. The error of k i and τ i obtained by the deconvolution method using the program Sound Analysis (Version 1.5) was close to 5 %.…”

“…1) differ in the length of the CH 2 chain and its terminal group (R 1 ) at the heterocyclic ring as well as in the character of side groups attached to the benzene ring (R 2 , R 3 ). It has been shown [6,7] that the molecular structure of Mero dyes influence their intra-and inter-actions, and as a result, the spectrally discernible species of the dye are formed, A. Dudkowiak (B) · E. Teślak · B. Olejarz Faculty of Technical Physics, Poznan University of Technology, Nieszawska 13A, 60 965 Poznań, Poland e-mail: alina.dudkowiak@put.poznan.pl e.g., protonated and/or free-base, showing different photophysical and photochemical properties.…”

“…However, the molecular mechanism responsible for the phototherapeutic role of Mero-sensitizer has not been clarified yet. The spectral properties and some photophysical parameters of seven stilbazolium Mero dyes in model systems have been reported [6,7]. The dyes investigated (Fig.…”

“…These processes are responsible for photosensitized oxidations involved in phototherapy, in photocarcionogenesis, and in photodegradation of dyes or polymers [8]. In this article, using the data obtained for Mero dyes in organic solvents and in mononuclear blood cells [6,7], the yield of singlet oxygen generation was determined. In addition, the mechanism and quenching rate constant of dye triplet states were estimated.…”