Photoswitchable aggregation-induced emission of a dithienylethene–tetraphenylethene conjugate for optical memory and super-resolution imaging

Abstract

We report the synthesis of a dithienylethene-tetraphenylethene (DTE-TPE) conjugated photochromic fluorophore which simultaneously exhibits aggregation-induced emission and reversible fluorescence switching. Photochromic DTE-TPE turns cyan-blue after 5 s of UV irradiation and exhibits a strong green emission at 520-540 nm upon excitation with visible light when present in nanoparticles and the solid state, in contrast to non-fluorescence in solution. DTE-TPE exhibits reversible fluorescence switching under alternating irradiation with UV and visible light (wavelengths greater than 440 nm), when present in nanoparticles and the solid state. The continuous readout of the emissive DTE-TPE film over 1 h upon 440 nm excitation-irradiation causes only a 7% reduction in emission intensity for DTE-TPE. The superresolution fluorescence nanolocalization indicates that the vicinal DTE-TPE emitters show sub-100 nm resolution which is higher than for conventional fluorescent imaging. The spectroscopic and imaging data provides initial guidelines for the screening of molecular scale memory units with the corresponding excitation and detection wavelengths for signal readout and super-resolution imaging agents.

A trident dithienylethene-perylenemonoimide dyad with super fluorescence switching speed and ratio

“…Evidently, fluorescence switching is more promising than photochromism in all-optical switches and transistors [7][8][9] . A great deal of efforts have been taken to develop novel photoswitchable fluorescent DTE derivatives with high fluorescence quantum yields (F F ), on/off ratios and switching speeds [10][11][12][13][14][15][16] . However, the performance of photoswitchable fluorescent DTEs is far from satisfactory owing to the scarcity of high-speed switching capability and large fluorescence on/off ratio.…”

Solvent-dependent fluorescence enhancement and piezochromism of a carbazole-substituted naphthopyran

“…The followed Claisen condensation between compound 2 and 2-naphthol succeeded in synthesizing CzNP was synthesized in yield of 65% with PTSA as catalyst in CH 2 Cl 2 . This final product was well characterized with 1 H NMR, 13 C NMR, IR, elemental analysis and mass spectrometry. The single crystal of CzNP was cultivated by the slow evaporation method and characterized by X ray single crystal diffraction analyses, which further confirmed the molecular structure of CzNP.…”

“…So far, diarylethene, spiropyran and spirooxazine derivatives have been extensively studied for constructing fluorescence-photochromism switches, whereas less attention has been paid to NP unit [11][12][13][14]. Up to now, only a few examples using photochromism of naphopyran to modulate the fluorescence via different ways, such as the binding of metal ion and protonation, photoinduced energy and electron transfer have been reported [15][16][17][18].…”

Intermolecular hydrogen bonding-assisted high contrast fluorescent switch in the solid state

“…In 2004, Park et al introduced AIEE cyano-substituted ethylene into DTE unit, and successfully realized the solid-state fluorescence switching [26,27]. Some other solid-emissive chromophores, such as tetraphenylethene [28], naphthalimide [29e31], perylenebisimide [32,33], can also be covalently linked to DTE to afford high contrast fluorescent switches in the solid state. However, covalent linking chromophore to DTE unit is synthetically tedious and arouses increased expense, which limits its practical applications.…”