Photophysical study of 2-fluorenyl-1,2,3-triazole-labeled 2⁰-deoxyuridine and its oligonucleotide

In this study, we prepared 2-fluorenyl-1,2,3-triazol-4-yl-2⁰ -deoxyuridine (U^FT) and inserted it at the central position of an oligodeoxynucleotide (ODN) to investigate whether the triazole group is an efficient linker between fluorene and uracil. U^FT displays different fluorescence intensities and emission maxima in different solvents, indicating its potential for application as an environmentally sensitive probe. Moreover, excimer emission from U^FT was observed in water. However, U^FT containing ODN did not exhibit selective thermal stability and fluorescence changes upon duplex formation with matched and single-base mismatched targets. This highlighted the importance of selecting the appropriate linker to connect the fluorophore to the nucleobase when developing such DNA probes.