Singlet oxygen (1O2), the lowest excited state of molecular oxygen,
is a fascinating species in many ways. Its chemistry
differs significantly from that of ground state triplet oxygen.
Singlet oxygen readily reacts with a wide range of biological
and organic materials which leads to their alteration and
Arguably the most important way of singlet oxygen formation
is the so-called photosensitizing process: A light excited
molecule of an appropriate dye - so called photosensitizer (PS) -
transfers energy to molecular oxygen giving rise
to singlet oxygen. Nature is figuratively full of such dyes
which support the formation of singlet oxygen, e.g. photosynthetic dyes
or Protoporphyrin IX (a precursor for heme).
Singlet oxygen is involved in a rich variety of diverse biochemical
processes, such as photosynthesis, cell signaling, immune responses
or polymer degradation
Research involving singlet
oxygen and the photosensitizing process has various perspectives
What we do
Both singlet oxygen and photosensitizers show weak near-infrared phosphorescence emission, which allows for their optical detection. The main research interest of our group is the developement and application of optical tools and methods for detection of singlet oxygen in various systems, e.g. solutions, solid and polymeric samples, cell cultures or even whole laboratory animals. Currently our main research tool is the unique experimental setup for measuring time- and spectral-resolved near-infrared luminiscence, which allows us to observe dynamics of interaction among photosensitizers, singlet oxygen, antioxidants and other biologically relevant molecules, e.g. [ Dedic (2007) J Mol Struct, Korinek (2004) J Fluorescence, Dedic (2003) J Luminescence ]. This tool is combined with methods of fluorescence, absorption and transient absorption spectroscopy. Lately we have been working on developement of setup for microscopic measurement of near-infrared luminiscence in order to investigate interactions of singlet oxygen directly in heterogenous environment of living cells. Such a fundamental research is necessary for successful progress of photodynamic therapy and a variety of other applications involving singlet oxygen.