The tetrapyrrole chlorin e6 (Ce6) is actively used in photodynamic therapy (PDT) and as a test drug for sonodynamic therapy due to its ability to generate singlet oxygen. In this work, we have analyzed the absorption, photoluminescence (PL), and PL excitation spectra of Ce6 molecules in a nutrient medium and inside the melanoma cells. An analysis of the results shows that Ce6 inside the cancer cells with a low pH remains in monomeric form. A photodynamic test has also been conducted that confirmed the photodynamic effect produced by Ce6 in cancer cells by changing the signals from Ce6 and cells in the absorption and PL spectra.
The effect of photoinduced processes on CdSe/ZnS quantum dots surface on the functionality of TiO2 nanoparticles/quantum dots hybrid structures was investigated. It is shown that preliminary irradiation of quantum dots makes it possible to achieve a threefold increase in the efficiency of electron transfer from quantum dot to TiO2 nanoparticle in these structures. It has been demonstrated that photoinduced processes affect both the quantum yield of quantum dots luminescence and the reactive oxygen species generation by structures under visible light.
A morphology and photoinduced changes of luminescence properties of two types of hybrid structures based
on TiO2 nanoparticles and CdSe/ZnS QDs were examined. A spin-coating method and a modified Langmuir-
Blodgett technique have been applied to form the multilayer hybrid structures on glass slides. It was
demonstrated that uniformity of QD surface concentration in hybrid structures depends on the method of
structure formation. A photodegradation of luminescence properties of the structures is associated with the
formation of QD aggregates. The QD aggregate concentration and their size depend on the method of the
structure formation and the concentration of TiO2 nanoparticles. A decay of luminescence of QD aggregates
in hybrid structures contains a microsecond components. An exposure of the hybrid structures with uniform
QD surface concentration by visible light resulted in a photopassivation of their surface, which is
accompanied by significant increase of luminescence quantum yield of QDs.
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