Ratiometric Near-Infrared Fluorescent Probes Based On Through-Bond Energy Transfer and π-Conjugation Modulation between Tetraphenylethene and Hemicyanine Moieties for Sensitive Detection of pH Changes in Live Cells
| Autor: | Wafa Mazi, Nathan Conner, Fen-Tair Luo, Jianheng Bi, Mingxi Fang, Haiying Liu, Jianbo Wang, Yibin Zhang, H. Peter Lu, Shuai Xia |
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| Rok vydání: | 2018 |
| Předmět: |
Cytoplasm
Fluorescence-lifetime imaging microscopy Intracellular pH Biomedical Engineering Pharmaceutical Science Bioengineering 02 engineering and technology 010402 general chemistry Ring (chemistry) Photochemistry 01 natural sciences Article chemistry.chemical_compound Morpholine Humans Bond energy Fluorescent Dyes Pharmacology Chemistry Optical Imaging Organic Chemistry Near-infrared spectroscopy Carbocyanines Hydrogen-Ion Concentration 021001 nanoscience & nanotechnology Fluorescence Acceptor 0104 chemical sciences Spectrometry Fluorescence 0210 nano-technology HeLa Cells Biotechnology |
| Zdroj: | Bioconjugate Chemistry. 29:1406-1418 |
| ISSN: | 1520-4812 1043-1802 |
| DOI: | 10.1021/acs.bioconjchem.8b00111 |
| Popis: | In this paper, we present three ratiometric near-infrared fluorescent probes (A–C) for accurate, ratiometric detection of intracellular pH changes in live cells. Probe A consists of a tetraphenylethene (TPE) donor and near-infrared hemicyanine acceptor in a through-bond energy transfer (TBET) strategy, while probes B and C are composed of TPE and hemicyanine moieties through single and double sp(2) carbon–carbon bond connections in a π-conjugation modulation strategy. The specific targeting of the probes to lysosomes in live cells was achieved by introducing morpholine residues to the hemicyanine moieties to form closed spirolactam ring structures. Probe A shows aggregation-induced emission (AIE) property at neutral or basic pH, while probes B and C lack AIE properties. At basic or neutral pH, the probes only show fluorescence of TPE moieties with closed spirolactam forms of hemicyanine moieties, and effectively avoid blind fluorescence imaging spots, an issue which typical intensity-based pH fluorescent probes encounter. Three probes show ratiometric fluorescence responses to pH changes from 7.0 to 3.0 with TPE fluorescence decreases and hemicyanine fluorescence increases, because acidic pH makes the spirolactam rings open to enhance π-conjugation of hemicyanine moieties. However, probe A shows much more sensitive ratiometric fluorescence responses to pH changes from 7.0 to 3.0 with remarkable ratio increase of TPE fluorescence to hemicyanine fluorescence up to 238-fold than probes B and C because of its high efficiency of energy transfer from TPE donor to the hemicyanine acceptor in the TBET strategy. The probe offers dual Stokes shifts with a large pseudo-Stokes shift of 361 nm and well-defined dual emissions, and allows for colocalization of the imaging readouts of visible and near-infrared fluorescence channels to achieve more precisely double-checked ratiometric fluorescence imaging. These platforms could be employed to develop a variety of novel ratiometric fluorescent probes for accurate detection of different analytes in applications of chemical and biological sensing, imaging, and diagnostics by introducing appropriate sensing ligands to hemicyanine moieties to form on–off spirolactam switches. |
| Databáze: | OpenAIRE |
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