Masked red-emitting carbopyronine dyes with photosensitive 2-diazo-1-indanone caging group

KIRILL KOLMAKOV; CHRISTIAN WURM; MAKSIM V. SEDNEV; MARIANO L. BOSSI ; VLADIMIR N. BELOV; STEFAN W. HELL

Photochemical and Photobiological Sciences

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2012 vol. 11 p. 522 - 532

1474-905X

Caged near-IR emitting fluorescent dyes are in high demand in optical microscopy but up to now were unavailable. We discovered that the combination of a carbopyronine dye core and a photosensitive 2- diazo-1-indanone residue leads to masked near-IR emitting fluorescent dyes. Illumination of these caged dyes with either UVor visible light (λ < 420 nm) efficiently generates fluorescent compounds with absorption and emission at 635 nm and 660 nm, respectively. A high-yielding synthetic route with attractive possibilities for further dye design is described in detail. Good photostability, high contrast, and a large fluorescence quantum yield after uncaging are the most important features of the new compounds for non-invasive imaging in high-resolution optical microscopy. For use in immunolabelling the caged dyes were decorated with a (hydrophilic) linker and an (activated) carboxyl group.