Abstract
A new setup for direct microspectroscopic monitoring of singlet oxygen (O-1(2)) has been developed in our laboratory using a novel near-infrared sensitive InGaAs 2D-array detector. An imaging spectrograph has been inserted in front of the 2D-array detector, which allows us to acquire spectral images where one dimension is spatial and the other is spectral.
The work presents a detailed examination of sensitivity and noise characteristics of the setup and its ability to detect O-1(2). The O-1(2') phosphorescence-based images and near-infrared luminescence spectral images recorded from single TMPyP-containing fibroblast cells reflecting spectral changes during irradiation are demonstrated.
The introduction of spectral images addresses the issue of a potential spectral overlap of O-1(2) phosphorescence with near-infrared-extended luminescence of the photosensitizer and provides a powerful tool for distinguishing and separating them, which can be applied to any photosensitizer manifesting near-infrared luminescence.