Production of Singlet Oxygen From (Eosin blue, Rosa Bengal and Safranin O) Dyes Using Coherent and Incoherent Light Sources

Abstract

In this work the possibility of production of singlet oxygen was investigated for three dyes, namely (Eosin blue, Rose Bengal and Safranin O) after irradiation by two light sources: the first is green diode laser with wavelength (532 nm) and 100 mW output power and the second is light emitting diode (LED) with wavelength (365 nm) and 1200 mW output power. The samples were prepared by dissolving Eosin blue in ethanol and then methanol and dissolving Rosa Bengal and Safranin O in distilled water. UV-VIS spectrometer model 6505 was used to record the absorption spectra of the samples and USB 2000 spectrometer connected to computer was used to record the emission spectra of the samples after different irradiation times starting from 30 seconds up to 120 seconds. The emission spectra were recorded and analyzed. The obtained results from Rose Bengal and Safranin O dyes both dissolved in distilled water showed indication for production of singlet oxygen (1O2), due to its emission bandat 634 nm which is one of the bands of singlet oxygen (1O2) after irradiation by green diode laser (532 nm). Therefore, these dyes can be used in the photodynamic therapy (PDT). Eosin blue dissolved in ethanol and methanol, separately and after irradiation by both sources didn’t show any indication for the production of singlet oxygen.