Single-Molecule Fluorescence Photoswitching of a Diarylethene−Perylenebisimide Dyad: Non-destructive Fluorescence Readout

Abstract

Single-molecule fluorescence photoswitching plays an essential role in ultrahigh-density (Tbits/inch 2 ) optical memories and super-high-resolution fluorescence imaging. Although several fluorescent photochromic molecules and fluorescent proteins have been applied, so far, to optical memories and super-highresolution imaging, their performance is unsatisfactory because of the absence of "non-destructive fluorescence readout capability". Here we report on a new molecular design principle of a molecule having non-destructive readout capability. The molecule is composed of acceptor photochromic diarylethene and donor fluorescent perylenebisimide units. The fluorescence is reversibly quenched when the diarylethene unit converts between the open-and the closed-ring isomers upon irradiation with visible and UV light. The fluorescence quenching is based on an electron transfer from the donor to the acceptor units. The fluorescence photoswitching and non-destructive readout capability were demonstrated in solution (an ensemble state) and at the single-molecule level. Femtosecond time-resolved transient and fluorescent lifetime measurements confirmed that the fluorescence quenching is attributed to the intramolecular electron transfer.

Nanoscopic Visualization of Soft Matter Using Fluorescent Diarylethene Photoswitches

“…[20][21][22] Despite their wide variability, the lack of derivatives in which the closed form has a strong fluorescence in the visible range has prevented their direct application in super-resolution imaging. Strategies to covalently link diarylethene switches with suitable fluorophores and to utilize the energy [23] or electron transfer [24] of the resulting multichromophoric systems have been successful, but require extended syntheses and result in rather large probes. Labeling structures with such extended probes can significantly alter the structures to be visualized.…”

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.…”

Probes for Nanoscopy: Photoswitchable Fluorophores

“…The two moieties are linked in a close proximity by a flexible or rigid spacer [26][27][28][29][30][31][32]. Although other mechanisms are possible (e.g., electron transfer [33][34][35] and electronic effects [36]), the preferred mechanism by which the photochromic reaction is transferred into a fluorescence modulation is usually F€ orster resonance energy transfer (FRET) [37], with the fluorophore (FL) acting as a donor and the two forms of the photochrome playing the role of a selective energy acceptor. The optimum situation for a good fluorescent switch is that only one of the isomers of the photochromic moiety acts as an efficient acceptor (acceptor isomer, AI), while the other is a poor one (neutral isomer, NI).…”