Colourimetric redox-polyaniline nanoindicator for in situ vesicular trafficking of intracellular transport

Eun Bi Choi, Jihye Choi, Seo Ryung Bae, Hyun Ouk Kim, Eunji Jang, Byunghoon Kang, Myeong Hoon Kim, Byeongyoon Kim, Jin Suck Suh, Kwangyeol Lee, Yong Min Huh, Seungjoo Haam

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


Vesicular pH modulates the function of many organelles and plays a pivotal role in cell metabolism processes such as proliferation and apoptosis. Here, we introduce a simple colorimetric redox-polyaniline nanoindicator, which can detect and quantify a broader biogenic pH range with superior sensitivity compared to pre-established trafficking agents employing one-dimensional turn-on of the fluorescence resonance-energy-transfer (FRET) signal. We fabricated polyaniline-based nanoprobes, which exhibited convertible transition states according to the proton levels, as an in situ indicator of vesicular transport pH. Silica-coated Fe3O4-MnO heterometal nanoparticles were synthesised and utilised as a metal oxidant to polymerise the aniline monomer. Finally, silica-coated polyaniline nanoparticles with adsorbed cyanine dye fluorophores Cy3 and Cy7 (FPSNICy3 and FPSNICy7) were fabricated as proton-sensitive nanoindicators. Owing to the selective quenching induced by the local pH variations of vesicular transport, FPSNICy3 and FPSNICy7 demonstrated excellent intracellular trafficking and provided sensitive optical indication of minute proton levels.

Original languageEnglish
Pages (from-to)1169-1179
Number of pages11
JournalNano Research
Issue number4
Publication statusPublished - 2015 Apr 1

Bibliographical note

Publisher Copyright:
© 2014, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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