title: Photophysics and photochemistry of zinc phthalocyanine/bovine serum albumin adducts.
abstract: Zinc phthalocyanine (ZnPc) is a well known Type II (singlet oxygen mediated) hydrophobic photosensitizer 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 chemiluminescence 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.
authors.affiliation: Facultad de Química, Departamento de Química Física, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Casilla 306, (536), Santiago, Chile.
authors.forename: Emilio
authors.initials: E
authors.lastname: Alarcón
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Edwards
authors.forename: Angélica M
authors.initials: AM
authors.lastname: Garcia
authors.forename: Marcelo
authors.initials: M
authors.lastname: Muñoz
authors.forename: Alexis
authors.initials: A
authors.lastname: Aspée
authors.forename: Claudio D
authors.initials: CD
authors.lastname: Borsarelli
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Lissi
mesh_terms: D007211:Indoles / Q000737:chemistry* / Q000528:radiation effects; D007259:Infrared Rays; D054833:Isoindoles; D010777:Photochemistry / Q000379:methods; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000528:radiation effects; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000528:radiation effects; D013053:Spectrophotometry; D018724:Spinacia oleracea / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D007211:Indoles; D054833:Isoindoles; D045332:Photosystem II Protein Complex; D012710:Serum Albumin, Bovine; C013647:phthalocyanine