The aim of the thesis was to synthesize new nucleosides, nucleotides and the corresponding DNA probes bearing various fluorescent labels, which can be used for bioanalytical applications. In the first part of the thesis, 2'-deoxycytidine and the corresponding nucleoside triphosphate bearing tryptophan-based imidazolinone fluorophore were synthesized by Sonogashira cross-coupling reaction. The fluorophore showed sensitivity to pH and viscosity. Nucleotide was used for the construction of modified oligonucleotides (ON) and DNA by primer extension (PEX) or polymerase chain reaction (PCR). Labelled ON probe was used for sensing interaction with single-strand binding protein, which resulted in increased fluorescence intensity of modified ON. Next, thymidine and thymidine triphosphate labelled by bezylidene- tetrahydroxanthylium fluorophore were synthesized by copper-catalyzed azide-alkyne cycloaddition (CuAAC). Fluorescence of the fluorophore is dependent on the polarity and viscosity of the environment. Incorporation of the modified nucleotide into DNA, by PEX or PCR, led to dramatic increase of the fluorescence presumably due to the interactions of the fluorophore in the major groove. Unfortunately, the modified nucleotide was not suitable for in cellulo imaging due to its cytotoxicity. The modified..
