Investigation of the Photosensitizing Action of Oxygen Dissolved in Aerated Aqueous Media under Excitation by Laser Radiation at 1070 and 1273 nm

Abstract

The rates of chemical trapping of singlet oxygen were studied in aerated water, ethanol, and deuterium oxide upon direct excitation of oxygen molecules by radiation of diode and fiber lasers, corresponding to the fundamental (1273 nm) and vibrational (1070 nm) absorption bands of oxygen molecules. As a trap, 1,3- diphenylisobenzofuran was used, which was solubilized in aqueous systems by adding 0.05 M sodium dodecyl sulfate. It is established that, just as in the organic media we have recently studied, in aerated alcohol and aqueous systems the quantum efficiency of the trap oxygenation under laser excitation at 1070 nm is two orders of magnitude lower than that under excitation at 1273 nm. The significance of these data for the use of IR lasers in phototherapy is discussed.