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Nano Research

Article Title

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

Authors

Eun Bi Choi, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Jihye Choi, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Seo Ryung Bae, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Hyun-Ouk Kim, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Eunji Jang, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Byunghoon Kang, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Myeong-Hoon Kim, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
Byeongyoon Kim, Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea
Jin-Suck Suh, Department of Radiology, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea
Kwangyeol Lee, Department of Chemistry, Korea University, Seoul 136-701, Republic of Korea
Yong-Min Huh, Department of Radiology, College of Medicine, Yonsei University, Seoul 120-752, Republic of Korea
Seungjoo Haam, Department of Chemical and Biomolecular Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea

Keywords

redox, pH, intracellular compartments, organic quencher, conducting polymer, nanoindicator

Abstract

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 polyanilinebased 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.

Graphical Abstract

Publisher

Tsinghua University Press

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