title: Mapping live cell viscosity with an aggregation-induced emission fluorogen by means of two-photon fluorescence lifetime imaging.
abstract: Intracellular viscosity is a crucial parameter that indicates the functioning of cells. In this work, we demonstrate the utility of TPE-Cy, a cell-permeable dye with aggregation-induced emission (AIE) property, in mapping the viscosity inside live cells. Owing to the AIE characteristics, both the fluorescence intensity and lifetime of this dye are increased along with an increase in viscosity. Fluorescence lifetime imaging of live cells stained with TPE-Cy reveals that the lifetime in lipid droplets is much shorter than that from the general cytoplasmic region. The loose packing of the lipids in a lipid droplet results in low viscosity and thus shorter lifetime of TPE-Cy in this region. It demonstrates that the AIE dye could provide good resolution in intracellular viscosity sensing. This is also the first work in which AIE molecules are applied in fluorescence lifetime imaging and intracellular viscosity sensing.
authors: Division of Biomedical Engineering, Department of Chemistry, Institute for Advanced Study, Division of Life Science, State Key Laboratory of Molecular Neuroscience, Institute of Molecular Functional Materials, Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong (China).
authors: Sijie
authors: S
authors: Chen
authors: Yuning
authors: Y
authors: Hong
authors: Yan
authors: Y
authors: Zeng
authors: Qiqi
authors: Q
authors: Sun
authors: Yang
authors: Y
authors: Liu
authors: Engui
authors: E
authors: Zhao
authors: Gongxun
authors: G
authors: Bai
authors: Jianan
authors: J
authors: Qu
authors: Jianhua
authors: J
authors: Hao
authors: Ben Zhong
authors: BZ
authors: Tang
mesh_terms: D003952:Diagnostic Imaging / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D014783:Viscosity
keywords: aggregation; fluorescent probes; imaging agents; microviscosity; sensors