Bright ESIPT emission from 2,6-di(thiazol/oxazol/imidazol-2-yl)phenol derivatives in solution, aggregation and solid states.
Panpan ChenZhigang NiuEenju WangPublished in: Methods and applications in fluorescence (2024)
Most luminophores often suffer from the problem of aggregation-caused quenching (ACQ) or fluorescence disappearance in dilute solution. It is significant to bridge the gap between ACQ and AIE. In this work, a facile but effective strategy was proposed for the fabrication of always-on luminophores based on the excited state intramolecular proton transfer (ESIPT) mechanism, and six luminophores emitting bright fluorescence in solution, aggregation and solid states were synthesized from 5-tert-butyl-2-hydroxyisophthalaldehyde. All these ESIPT systems show only keto emission owing to their congested structures which block the breakage of intramolecular hydrogen bond (O-H•••N) by solvation, and subsequently make enol emission impossible. Three of these luminophores are prone to convert into the corresponding phenolate anions emitting blue-shifted emission, which enable them to sense pH variation in the weakly basic range. Furthermore, white-light emission was achieved by combining two of them which show complementary-color fluorescence, and one of them was utilized for bioimaging of living Hela cells and the high-resolution image was obtained.
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Keyphrases
- fluorescent probe
- energy transfer
- living cells
- quantum dots
- solid state
- high resolution
- single molecule
- induced apoptosis
- cell cycle arrest
- ionic liquid
- light emitting
- deep learning
- molecular dynamics
- escherichia coli
- oxidative stress
- gold nanoparticles
- signaling pathway
- visible light
- pi k akt
- cell proliferation
- electron transfer