pH Responsive Two-Photon Absorbing Functionalized Styrylpyridine-Based Multi-Branched Dyes
David Kréher, Fabrice Mathevet, Patrice Baldeck, Clément Ricard, Boudewijn van der Sanden and André-Jean Attias
We report on the design, synthesis and optical properties of new two-photon absorbing multi-branched chromophores, based on a pyridine core. Measurements of TPA using the two-photon fluorescence method in the fs regime indicate that these chromophores exhibit two-photon absorption. We show that a change of the substitution of the electron-acceptor core influences significantly the TPA cross sections. Moreover, upon protonation, the TPA properties are greatly enhanced in the 700-900 nm range. Thus, these molecules can be used as pH-sensitive TPA dyes. Preliminary results related to biological applications will be presented as well.
Keywords: nonlinear optics, third-order effect, two-photon absorption, multibranched dye, styrylpyridine, pH responsive.