Vinyl‐Pyridinium Triphenylamines: Novel Far‐Red Emitters with High Photostability and Two‐Photon Absorption Properties for Staining DNA

Abstract

A series of mono-, bis- and trisvinyl-pyridinium triphenylamines (TP-py) has been synthesised and evaluated for its one- and two-photon absorption (2PA) induced-fluorescence properties under biological conditions. Interestingly, these compounds are only weakly fluorescent in water, whereas their fluorescence emissions are strongly restored (exaltation factors of 20-100) upon binding to double-stranded DNA. Additional measurements in glycerol indicate that the fluorescence increases are the result of immobilisation of the dyes in the DNA matrix, which inhibits rotational de-excitation modes. This particular feature is especially remarkable in the case of the bis and tris derivatives (TP-2 py, TP-3 py), which each display a high affinity (K(d) ~ microM) for dsDNA. TPIF measurements have shown that TP-2 py and TP-3 py each have a large 2PA cross section (delta up to 700 GM) both in glycerol and in the presence of DNA, which ranks them amongst the best 2PA biological fluorophores. Finally, one- and two-photon confocal imaging in cells revealed that these compounds perform red staining (lambda(em)=660-680 nm) of nuclear DNA with excellent contrast. The remarkable optical properties of the TP-py series, combined with their high photostability and their easy synthetic access, make these compounds extremely attractive for use in confocal and 2PA microscopy.

Carbazole tricationic salt: A novel potential two-photon fluorescent DNA probe for nucleic imaging of cells

“…For two-photon fluorescence probes, Φ × δ is significantly important, and is responsible for high contrast [38]. The Φ × δ of THEPC in the presence of DNA (ratio: 70) is 33.3 GM, larger than TP-3py (9.1 GM) [21], which ranks THEPC as a good biological fluorophore. From Figure 4(b) and Figure 5, in both one-photon and two-photon fluorescent titration, the fluorescent intensity evidently increased with the addition of DNA.…”

“…Recently, Allain et al developed a trisvinyl-pyridinium triphenylamine (TP-3py) with a Φ × δ value about 9.1 GM in the presence of herring testes DNA, which can image nuclear DNA in paraformaldehyde-fixed CHO K1 cells by TPM (excitation 840 nm) [21,22]. In this article, a novel carbazole tricationic salt with larger Φ × δ (33 GM in the presence of calf-thymus DNA), THEPC, was synthesized and characterized.…”

Synthesis and Characterization of Red‐Emitting Poly(aryleneethynylene)s Based on 2,5‐Bis(2‐ethylhexyl)‐3,6‐di(thiophen‐2‐yl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione (DPP)

“…The melting point and 1 H NMR data of the compound agreed well with literature data. [28] Yield: 82%. (2) Pd(PPh 3 ) 2 Cl 2 (167 mg, 0.24 mmol) and CuI (90 mg, 0.478 mmol) were added to a solution of 1 (3 g, 5.98 mmol) in dry THF (25 mL) and diisopropylamine (25 mL).…”

Self-assembly: mastering photonic processes at nanoscale

“…As an example, 3D ordering of fluorescent dyes through their spontaneous interactions with double stranded DNA can be taken into profit for efficient noncovalent DNA labelling [57]. A series of vinyl−pyridinium triphenylamines (TP−Py) derivatives was recently proposed and evaluated for its one− and two−photon absorption (2PA) induced−fluorescence pro− perties under biological conditions [58,59]. Interestingly, these compounds exhibit large stokes shifts resulting in red to far red emission.…”