Determination of the singlet oxygen quantum yield of bacteriochlorin a: a comparative study in phosphate buffer and aqueous dispersion of dimiristoyl-L-alpha-phosphatidylcholine liposomes.

The production of singlet oxygen (1O2) by bacteriochlorin a (BCA) was studied in phosphate buffer and in dimyristoyl-L-alpha-phosphatidylcholine (DMPC) unilamellar liposomes. The comparative method used to measure 1O2 production was a quantitative analysis of photooxidation reactions leading to the loss of absorbance of the water-soluble specific probe: anthracene-9,10-dipropionic acid. Rose Bengal, whose 1O2 quantum yield (phi(RB)) is well known in alcohols and phosphate buffer, was used as the standard for the quantification of the BCA singlet oxygen production.

Effect of aggregation on bacteriochlorin a triplet-state formation: a laser flash photolysis study.

Bacteriochlorin a (BCA) is a potential photosensitizer for photodynamic therapy of cancer. It has been shown previously that the photoefficiency of the dye is mainly dependent on singlet oxygen (1O2) generation. Nanosecond laser flash photolysis was used to produce and to investigate the excited triplet state of the dye in methanol, phosphate buffer and dimiristoyl-L-alpha-phosphatidylcholine (DMPC) liposomes.