Fluorescence Turn‐on of Tetraphenylethylene Derivative by Transfer from Cyclodextrin to Liposomes, HeLa Cells, andE. coli

Abstract

Herein, trimethyl‐β‐cyclodextrin (TMe‐β‐CDx) and γ‐cyclodextrin (γ‐CDx) could dissolve a tetraphenylethylene derivative (TPE−OH4) in water through high‐speed vibration milling. The fluorescence intensity of the TMe‐β‐CDx−TPE−OH4 complex was much higher than that of the γ‐CDx−TPE−OH4 complex, as the rotation of the central C=C double bond of TPE−OH4 after photoactivation was inhibited in a smaller TMe‐β‐CDx cavity in comparison with the γ‐CDx cavity. In contrast, the fluorescence intensity of the γ‐CDx−TPE−OH4 complex was very weak; nevertheless, it increased after the addition of liposomes due to the transfer of TPE−OH4 from the γ‐CDx cavity to the lipid membrane as a “turn‐on” phenomenon. Furthermore, to apply temperature sensor, it was demonstrated that the fluorescence intensity in the liposomes depended on the phase‐transition temperature. By using the fluorescence turn‐on phenomenon, TPE−OH4 could detect the presence of HeLa cells and E. coli by fluorescence.

Oligosaccharide Sensing Using Fluorophore-Probed Curdlans in Aqueous Media

“…Hence, in this study, we focused on tetraphenylethylene (TPE) as an aggregation-induced emission luminogen (AIEgens). The TPE chromophore is known to have an aggregated state that fluoresces strongly; however, a monomeric state does not emit based on the degree of restriction of intramolecular rotations (radiationless deactivation path) of the phenyl rings. , In fact, TPE-based fluorescence chemosensors are energetically investigated. − Thus, we synthesized a variety of degrees of substitution (DSs) of TPE-conjugated Curs ( TPE-Cur s, Figure f, left); an appropriate equivalent of 4-(1,2,2-triphenylvinyl)­benzoic acid (TPE-COOH, Figure f, center) was reacted with native Cur, which was swollen in N -methyl-2-pyrrolidinone prior to the reaction, in the presence of condensation reagents (see the Synthesis and Characterization section in the Supporting Information). Controlling the addition amounts of TPE-COOH enabled us to obtain various DS of TPE-Cur s, which allowed us to evaluate the effects of DS, particularly for the sensitivity toward acarbose (vide infra).…”

“On‐Off” Switching of Functional Guest Molecules via Exchange of Natural Product Solubilizing Agents

“…[52] The concentrations of 8 in TMe-β-CDx and γ-CDx complexes were determined to be 1.9 and 1.6 mM, respectively, by the absorbance after evaporation and dissolution in dimethyl sulfoxide (DMSO). [52] Owing to the strong fluorescence intensity of the TMe-β-CDx-8 complex by emission from a monomer in the TMe-β-CDx cavity, the photorotation of the central C=C double bond in a TMe-β-CDx-8 complex was inhibited via inclusion in the cavity of two TMe-β-CDxs. [53][54][55] In contrast, the γ-CDx-8 complex showed scarce fluorescence intensity because the rotation was not inhibited in the larger cavity of two γ-CDxs.…”

“…When HeLa cells and E. coli were treated with the γ-CDx-8 complex for 24 h and 30 min, respectively, at 37 °C, strong fluorescence intensities were observed in both cases. [52] Figure 3. Chemical structures of azobenzene ( 5), stilbene (6), tetraphenylethylene (7), and a tetraphenylethylene derivative (8).…”

“…Tetraphenylethylene (Figure 3, 7 ), which is a typical aggregation‐induced emission luminogen, did not form a complex with CDxs. In contrast, the tetraphenylethylene derivative 8 (Figure 3) was dissolved in water via the formation of complexes with 2,3,6‐tri‐ O ‐methyl‐β‐cyclodextrin (TMe‐β‐CDx) and γ‐CDx [52] . The concentrations of 8 in TMe‐β‐CDx and γ‐CDx complexes were determined to be 1.9 and 1.6 mM, respectively, by the absorbance after evaporation and dissolution in dimethyl sulfoxide (DMSO) [52] .…”

“…In contrast, the tetraphenylethylene derivative 8 (Figure 3) was dissolved in water via the formation of complexes with 2,3,6‐tri‐ O ‐methyl‐β‐cyclodextrin (TMe‐β‐CDx) and γ‐CDx [52] . The concentrations of 8 in TMe‐β‐CDx and γ‐CDx complexes were determined to be 1.9 and 1.6 mM, respectively, by the absorbance after evaporation and dissolution in dimethyl sulfoxide (DMSO) [52] . Owing to the strong fluorescence intensity of the TMe‐β‐CDx‐ 8 complex by emission from a monomer in the TMe‐β‐CDx cavity, the photorotation of the central C=C double bond in a TMe‐β‐CDx‐ 8 complex was inhibited via inclusion in the cavity of two TMe‐β‐CDxs [53–55] .…”