A new photoactivatable near-infrared-emitting QCy7 fluorophore for single-molecule super-resolution microscopy

Abstract

A new photoactivatable fluorophore based on a quinone-cyanine-7 (QCy7) scaffold was synthesized and spectroscopically characterized. The fluorophore exhibits fluorescence in the near-infrared spectral window and a large Stokes shift. Its application in super-resolution microscopy as an antibody bioconjugate is demonstrated.

Photoactivatable BODIPY Platform: Light-Triggered Anticancer Drug Release and Fluorescence Monitoring

“…10,11 Selective activation of these photoresponsive molecules allows for the microscopic study of biological systems in a temporally and spatially defined manner. Caged dye construction features an organic fluorophore (i.e., fluorescein, 12−15 rhodamine, 16−21 BODIPY, 22−27 cyanine, 28,29 and coumarin 5,30 derivatives) that is caged with a photolabile group, among which o-nitrobenzyl derivatives are the most commonly used. 31−35 Cleavage is accompanied by the modulation of photoinduced electron transfer (PeT), 14,22−25 fluorescence resonance energy transfer (FRET), 36 or excited state intramolecular proton transfer (ESIPT) 37,38 processes to provide a more emissive photoproduct.…”

Photochemically Active Dyes for Super-Resolution Microscopy

“…The two methoxy groups shift the absorption to longer wavelengths to allow for efficient photoactivation at 405 nm, increasing the compatibility of the probes with standard fluorescence microscopes. [27,28] Several fluorophores containing fluorescein and rhodamine derivatives, [29][30][31] silicon rhodamines, [32] and a quinonecyanine-derivative [33] have been modified with NB and NVOC and successfully applied for SMLM experiments. The popularity of this photoactivatable group arises from its relatively easy preparation and the out can only be obtained by permanent photobleaching.…”

Oxime as a general photocage for the design of visible light photo-activatable fluorophores

“…19 Examples of efficient photoactivatable uorophores include structures based on o-nitrobenzyl or its derivatives, phenacyl, 2diazoketone, acridinyl, azidophenyl, coumarinyl and o-hydroxynaphthyl moieties. 3,4,6,16,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] However, these photocaged dyes are generally characterized by relatively large sizes, poor water solubility, and poor biocompatibility, properties that greatly limit their biological applications. 4 To minimize side effects resulting from the use of UV light, investigators have developed sensitizer-assisted light-induced cleavage 20,39 and multiphoton activation strategies, 40,41 resulting in efficient photocage cleavage with visible or near-infrared light.…”