Mapping live cell viscosity with an aggregation-induced emission fluorogen by means of two-photon fluorescence lifetime imaging

Sijie Chen, Yuning Hong, Yan Zeng, Qiqi Sun, Yang Liu, Engui Zhao, Gongxun Bai, Jianan Qu, Jianhua Hao, Ben Zhong Tang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

65 Citations (Scopus)


KGaA. 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.
Original languageEnglish
Pages (from-to)4315-4320
Number of pages6
JournalChemistry - A European Journal
Issue number11
Publication statusPublished - 9 Mar 2015


  • aggregation
  • fluorescent probes
  • imaging agents
  • microviscosity
  • sensors

ASJC Scopus subject areas

  • Chemistry(all)

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