A Dicyanocarbazolylstilbene‐Derived Two‐Photon Fluorescence Probe for Lipid Raft with a Large Two‐Photon Action Cross Section

Abstract

Lipid raft is a microdomain which is rich in cholesterol and sphingolipid in the cytoplasmic membrane, and closely related to neurodegenerative diseases such as Alzheimer's disease and prion disease. Hence the study on the physiological mechanism of lipid raft is helpful to reveal its biological role and its correlations with diseases. Two-photon fluorescence probe for lipid raft is a sharp tool to achieve this goal. A dicyanocarbazolylstilbene-derived two-photon fluorescence probe for lipid raft (DLR) with a large two-photon action cross section (Φδ) was developed. DLR belongs to push-pull electronic architecture (Donor-Bridge-Receptor, D-π-A), and its maximum emission wavelength increased with medium polarity while its fluorescence intensity (FI) augmented with viscosity, and FI in DPPC (dipalmitoylphosphatidylcholine) was 20 times higher than that in DOPC (dioleoylphosphatidylcholine). Its fluorescence lifetime in DPPC was more than 2.2 times longer than that in DOPC. These indicates that DLR can distinguish DPPC from DOPC. Φδs of DLR in DPPC and DOPC were 1350 GM and 67 GM, respectively. DLR can image lipid raft distribution in cells and tissues.

Dicyanostilbene‐Derived Highly Sensitive Two‐Photon Fluorescence Temperature Probe for Live Cell Imaging

“…In previous exploration, we found that flexible substituents on the amino group not only significantly reduced the fluorescence quantum yield (Φ) and δ TPA [22][23][24][25][26] of a probe; but also increased the dependence on viscosity, which in turn, can highly weaken the dependence on temperature, thus giving rise to large measurement error. Therefore, we introduced a planar rigid 9-carbazolyl group at the amino terminus of DCS, which is a large aromatic ring and can further expand the molecular aromatic system with planar rigidity, thus significantly increasing the molecular Φ and δ TPA , and the dependence of the molecule on temperature.…”

“…The reported two-photon fluorophore DCS (4-methyl-2,5dicyano-4'-amino stilbene) with a very large TPA cross section (δ TPA ) has been successfully applied in the designs and developments of various TPF probes. [21][22][23][24] DCS is a push-pull chromophore with donor-π-acceptor (D-π-A) architecture. Its rationality and optimization in structural design have been proved by the literature.…”