ANNIHILATION DELAYED FLUORESCENCE OF PROBES AS A TUMOR OXYGEN LEVEL INDICATOR
The decay kinetics of erythrosine delayed luminescence in malignant and healthy biological tissues of laboratory mice was investigated. Upon periodical pulse excitation of luminescence an effect of delayed fluorescence suppression was discovered. The glow quenching value is dependent on the laser pulses repetition period. It is shown that the effect is associated with the decrease in the contribution of luminescence via photogenic annihilation reaction of triplet sensitizer and singlet oxygen excited states. In addition, the oxygen-dependent fluorescence decay affecting to the phosphorescence intensity is discussed. The obtained data suggest that it is possible to evaluate intensive oxygen consumption into a tissue using annihilation delayed fluorescence.