NIR-to-NIR two-photon bio-imaging using very bright tailored amino-heptamethines dyes

Simon Pascal (1, 2) , San-Hui Chi (3) , Alexei Grichine (4) , Veronique Martel-Frachet (4) , Joseph Perry (3) , Olivier Maury (2) , Chantal Andraud (2)

1 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
2 LC - Laboratoire de Chimie - UMR5182
3 Georgia Institute of Technology [Atlanta]
4 IAB - Institute for Advanced Biosciences / Institut pour l'Avancée des Biosciences (Grenoble)

Amino-heptamethines are highly conjugated cationic dyes featuring electronic absorption in the red region and strong nearinfrared (NIR) fluorescence. Unlike their parent chloro-heptamethine cyanines, the substitution of the central position of their polymethine skeleton with an amine confers them a high Stokes shift. This work reports the synthesis of aminoheptamethines and the investigation of their optical properties, including two-photon absorption in the NIR and shortwave infrared (SWIR) ranges, which has been overlooked for such chromophores so far. Their structures were tailored, introducing selected substitutuents on the indolenine moieties to modulate their hydrophobic/hydrophilic balance and investigate their potential as NIR-to-NIR two-photon probes for the bio-imaging of living cells.

Mots clés: Polymethine; Two-photon absorption; Near-infrared; Bio-imaging; Fluorescence

Domaines: Chimie organique; Ingénierie biomédicale; Optique / photonique

Simon Pascal, San-Hui Chi, Alexei Grichine, Veronique Martel-Frachet, Joseph Perry, et al.. NIR-to-NIR two-photon bio-imaging using very bright tailored amino-heptamethines dyes. Dyes and Pigments, 2022, 203, pp.110369. ⟨10.1016/j.dyepig.2022.110369⟩. ⟨hal-03656184⟩