Two spirobifluene-based turn-on fluorescent probes for highly selective detection of Cysteine and the applications in cells two-photon fluorescence imaging

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Vol. 316; p. 124342
• Main Authors: Hui, Yufeng, Guo, Hongda, Liu, Yeshen, Zhang, Ji, Xiao, Haibo
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 05.08.2024
• Subjects: Cell imaging; Cysteine detection; Fluorescent probe; Spirobifluene; Two-photon absorption; Two-photon absorption; Cysteine detection; Cell imaging; Spirobifluene; Fluorescent probe
• ISSN: 1386-1425; 1873-3557
• DOI: 10.1016/j.saa.2024.124342

[Display omitted] •Two spirobifluene-based turn-on fluorescent probes for Cysteine were synthesized.•The probes shows highly selectivity for Cysteine.•The probes had been applied to imaging Cysteine under two-photon excitation.•One probe displayed excellent detection limit for Cysteine. Two spirobifluene-based fluorescent probes SPF1 and SPF2, were designed and synthesized. The probes displayed “turn-on” fluorescence response for Cysteine. One of the challenges in developing a Cysteine probe is to secure high selectivity. SPF1/SPF2 can discriminate Cysteine from GSH as well as Hcy, and showed high substrate selectivity. The detection limit of SPF1 is 36 nM, which is excellent comparing with other optical sensors for Cysteine. The sensing mechanism of SPF1/SPF2 was verified by experimental data and theoretical calculations. There was a good linear relationship between the fluorescence intensity of SPF1/SPF2 and the concentration of Cysteine. The MTT tests indicated that SPF1/SPF2 had low cytotoxicity and good biocompatibility. Theoretical calculations demonstrated that SPF1, SPF2, and their related reaction products with Cysteine exhibited good two-photon absorption properties. Finally, SPF1/SPF2 had been successfully applied to the imaging of Cysteine in living cells under two-photon excitation.