A novel pH fluorescent probe based on indocyanine for imaging of living cells

Weifen Niu, Ming Nan, Li Fan, Ricky M S WONG, Shaomin Shuang, Chuan Dong*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

23 Citations (Scopus)


In this paper, we report a novel pH fluorescent probe, 1,1-dimethyl-2-((E)-2-(pyridin-4-yl)vinyl)-1H-benzo[e]indole (PVBI), for imaging in living cells via ethylene bridging of indole derivatives and pyridine. The pH titration indicated that the probe exhibits sensitive pH-dependent behavior with pKa 3.87 and responded linearly and rapidly to minor pH fluctuations within the range of 3.0-4.6 (linear coefficient of 0.9968). Thus PVBI could be potentially useful for quantitative determination of pH within the acidic window. Also, PVBI displays a notably large Stokes shift of 93 nm which could effectively reduce the excitation interference. Moreover, PVBI possesses highly selective response to H+ over various metal ions, good photostability and excellent reversibility. The confocal laser scanning microscope images for PVBI diffusing into cells in real-time and detection of pH in living cells were achieved successfully, suggesting the probe has excellent cell membrane permeability and could be applied to monitor pH fluctuations in living cells.

Original languageEnglish
Pages (from-to)224-231
Number of pages8
JournalDyes and Pigments
Publication statusPublished - 1 Mar 2016

Scopus Subject Areas

  • Chemical Engineering(all)
  • Process Chemistry and Technology

User-Defined Keywords

  • Cellular imaging
  • Confocal laser scanning microscope
  • Extreme acidity
  • Indocyanine
  • Membrane permeability
  • pH fluorescent probe


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