Synthesis and spectroscopic properties of fluorescent 5-benzimidazolyl-2'-deoxyuridines 5-fdU probes obtained from o-phenylenediamine derivatives.

Fluorescent nucleosides (dU(bmz)) with desirable fluorescence quantum yield (Φ) are synthesized from almost non-fluorescent 5-fdU and o-phenylenediamine derivatives. The fluorescence of these nucleosides is quite sensitive to pH and organic solvents. 4-Methoxybenzene-1,2-diamine was used for the detection of 5-fdU among natural nucleosides.