Influence of the oxazole ring connection on the fluorescence of oxazoyl-triphenylamine biphotonic DNA probes.

On the basis of our previous work on DNA fluorophores derived from vinylpyridinium-triphenylamine, we explored the structure space around the electron-rich triphenylamine (TP) core by changing the vinyl bond to an oxazole ring. As 2,5-diaryloxazoles are known to be highly fluorescent and efficient two photon absorbers, we synthesized analogues with two different connections of the oxazole to the triphenylamine core: TP-Ox2Py and TP-Ox5Py sets. Since the benzimidazolium group was proven to be more effective in the TP series than the pyridinium, we also synthesized a TP-Ox5Bzim set.

DNA switches on the two-photon efficiency of an ultrabright triphenylamine fluorescent probe specific of AT regions.

We report on the design and synthesis of two-photon fluorescent triphenylamines bearing two or three vinyl branches terminated by a N-methyl benzimidazolium moiety. The new compounds (TP-2Bzim, TP-3Bzim) are light-up fluorescent DNA probes with a long wavelength emission (>580 nm). Compared to their pyridinium models, the TP-Bzim dyes exhibit a remarkable improvement of both their DNA affinity and fluorescence quantum yield, especially for the two-branch derivative (TP-2Bzim: ΦF = 0.

An optimized alkyl chain-based binding motif for 2D self-assembly: a comprehensive crystallographic approach.

Taking into account substrate crystallographic constraints, an overarching molecular binding motif has been designed to allow transferable self-assembling patterns on different substrates. This optimized clip demonstrates robust and equivalent self-assembled architectures on both highly oriented pyrolitic graphite (HOPG) and reconstructed Au(111) surfaces.

Vinyl-triphenylamine dyes, a new family of switchable fluorescent probes for targeted two-photon cellular imaging: from DNA to protein labeling.

On the basis of our previous work on vinyl-triphenylamine derived DNA fluorophores we explored the structure space around this core by coupling it to diverse cationic, anionic and zwitterionic groups in the aim of targeting different classes of biomolecules. In parallel core modifications were performed to optimize the photophysical properties (quantum yield, two-photon absorption). The resulting water soluble π-conjugated molecules are called TP dyes and display an exceptional combination of optical properties: high two-photon absorption cross-section, high photostability, no self-quenching, and switchable fluorescence emission when bound to a biopolymer matrix.

N-phenyl-carbazole-based two-photon fluorescent probes: strong sequence dependence of the duplex vs quadruplex selectivity.

Herein we report on the synthesis and DNA recognition properties of a series of three N-phenyl carbazole-based light-up probes initially designed for two-photon absorption. The vinylic derivatives (Cbz-2Py, Cbz-3Py) display strong fluorescence enhancement when bound to various duplex- and quadruplex-forming oligonucleotides whereas the oxazole derivative is not fluorescent in DNA. Determination of affinity constants by fluorimetric titrations evidenced that Cbz-2Py has a clear preference for AT-rich duplex structures.