Photophysics and Photochemistry of Zinc Phthalocyanine/Bovine Serum Albumin Adducts

E. ALARCÓN; A. M. EDWARDS; A. M. GARCIA; M. MUÑOZ; A. ASPÉE; C. D. BORSARELLI; E. A. LISSI

Photochemical and Photobiological Sciences

Royal Society of Chemistry

Año: 2009 vol. 8 p. 255 - 263

1474-905X

Zinc phthalocyanine (ZnPc) is a well known Type II (singlet oxygen mediated) hydrophobicphotosensitizer with potential use in PDT. We have found that the presence of bovine serum albumin diminishes the aggregation degree of ZnPc in aqueous solution, indicating that albumins could be potentially useful carriers for this type of photosensitizer in PDT. In order to explore the photochemical and photophysical behavior of ZnPc associated to the protein, we have evaluated triplet excited state lifetime and yield, dye bleaching, oxygen consumption, formation of carbonyls and peroxides, and the spontaneous chemiluminiscence emitted after photolysis. The results show that dye association to BSA modifies the photophysics and photochemistry of ZnPC. In particular the decreased yield of long lived triplets suggests singlet state and/or static triplet quenching of the bound dye by the host protein.