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

• Published in: Chemistry : a European journal 2023-02, Vol.29 (10), p.e202203071-n/a
• Main Authors: Masuda, Kosuke, Omokawa, Riku, Kawasaki, Riku, Mise, Yuta, Ooyama, Yousuke, Harada, Shogo, Shinoda, Wataru, Ikeda, Atsushi
• Format: Article
• Language: English
• Subjects: Chemistry; Cyclodextrin; Cyclodextrins; Cyclodextrins - chemistry; E coli; Escherichia coli; Fluorescence; fluorescence probes; HeLa Cells; host-guest systems; Humans; Lipids; Liposomes; molecular dynamics; Photoactivation; Temperature sensors; Transition temperature; Transition temperatures
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202203071

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. It's fluorescence time! Although the tetraphenylethylene derivative (TPE−OH4) was fluorescence OFF state in γ‐cyclodextrin (γ‐CDx), the fluorescence turn‐on was observed in the liposomes, HeLa cells, and E. coli, because TPE−OH4 was transferred from the γ‐CDx cavity to the lipid or cell membranes.