3,6-Bis-<i>β</i>-Dicarbonylsubstituted Carbazoles Bearing N-Spacers and Their Eu(III) Complexes as Immunofluorescent Labelling Agents

Abstract

New reagents for immunofluorescence analysis of carbazole series containing fluorinated β -dicarbonyl fragments and carboxylic substituent groups separated by spacers of different lengths from the light-gathering carbazole scaffold have been developed. The markers in complex with Eu 3+ ions possess stability in the aqueous phase, intense and prolonged luminescence ( τ 550 - 570 μs) with characteristic emission maxima in the region of 615 nm and excitation wavelengths in the region of 380 - 390 nm, which distinguishes them from most of the analogs used. In the study of marker conjugation with streptavidin, a reagent containing 4 - 5 europium labeling complexes based on spacer-containing carbazole tetraketone was obtained. The marker-doped silicate nanoparticles exhibit intense and long-lived luminescence in the characteristic region.