A Simple Fluorescent Probe for Sensing pH and its Application in E. coli Cells

  • Jianbin ChaoEmail author
  • Xiaolu Wang
  • Yongbin Zhang
  • Fangjun Huo
  • Caixia Yin
  • Miao Xu


We designed and synthesized a simple fluorescent probe, (E)-2-(2-(3,4,5-Trimethoxybenzylidene)hydrazinyl) benzothiazole (probe), which could be applied to the detection of strongly acidic and alkaline pH in DMSO/water (1/4, v/v) system. It could be used to quantitatively detect strong acid in the range of 2.60–3.53 with a pKa of 2.78. Meanwhile, it also showed an excellent linear relationship between the fluorescence intensity and alkaline pH values over the range of 9.98–10.95 with a pKa of 9.32. The probe exhibited excellent properties to pH with high selectivity and sensitivity. The mechanism studies showed that the H+ binding with the N atom of benzothiazole moiety and hydrazine moiety in acid solution while the deprotonation of N atom in hydrazine group in basic environment. Importantly, the probe was successfully applied for imaging the strongly acidic and alkaline in E.coil cells.


Fluorescent probe pH-sensitive Extremely acid and alkaline Bio-imaging 



The work was supported by the National Natural Science Foundation of China (No. 21472118, 21672131), the Program for the Top Young and Middle-aged Innovative Talents of Higher Learning Institutions of Shanxi (No. 2013802), Talents Support Program of Shanxi Province (No. 2014401), Shanxi Province Outstanding Youth Fund (No. 2014021002), Natural Science Foundation of Shanxi Province of China (No. 201701D121018).

Supplementary material

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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Jianbin Chao
    • 1
    Email author
  • Xiaolu Wang
    • 1
    • 2
  • Yongbin Zhang
    • 3
  • Fangjun Huo
    • 3
  • Caixia Yin
    • 4
  • Miao Xu
    • 1
    • 2
  1. 1.Scientific Instrument CenterShanxi UniversityTaiyuanChina
  2. 2.School of Chemistry and Chemical EngineeringShanxi UniversityTaiyuanChina
  3. 3.Research Institute of Applied ChemistryShanxi UniversityTaiyuanChina
  4. 4.Institute of Molecular ScienceShanxi UniversityTaiyuanChina

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