Juryang Bae
Pohang University of Science and Technology, Korea
Title: Novel two-photon dyes: minimal autofluorescence in tissue imaging
Biography
Biography: Juryang Bae
Abstract
The advantage of fluorescent imaging for biomaterials is operationally simple, cost-effective, noninvasive, highly sensitive detection and visualization of organisms at a subcellular level.1 In tissue imaging, however, autofluorescence from biological molecules under excitation at UV−Vis wavelengths lowers signal to noise ratio. Most of biomolecules absorb and emit light of green region. So a novel class of fluorophores excited in the near-infrared region is necessary to suppress this critical issue. Two-photon absorbing dyes are one of the methods to satisfy this criterion. They have several advantages not only reduced autofluorescence, but also increased penetration depth, and high special-resolution. In addition, they diminish photodamage and photobleaching as well.2 Acedan, 6-acetyl-2-(dimethylamino)naphthalene, and its derivatives are widely used for two-photon dyes.3 But their maximum absorption wavelengths (~370 nm) are rather short for two-photon excitation (~740 nm) which shows strong autofluorescence and limits the depth in tissue in microscopic imaging of tissues. Herein, we have developed compact π-extended acedan derivatives. They have the longer maximum absorption wavelengths more than 400 nm and sufficient two-photon absorption properties. One of the new dyes that can be excitable at 1000 nm under two photon excitation condition is photochemically stable, biocompatible. Also it has environment-sensitivity and readily penetrated the blood−brain barrier, allowing in vivo fluorescence imaging of Aβ plaques in a live mouse model of Alzheimer’s disease.