A General Strategy for Through‐Bond Energy Transfer Fluorescence Probes Combining Intramolecular Charge Transfer: A Silyl Ether System for Endogenous Peroxynitrite Sensing

• Published in: Chemistry : a European journal Vol. 25; no. 71; pp. 16350 - 16357
• Main Authors: Lu, Gonghao, Guo, Yuxin, Zhuo, Jiezhen, Li, Xue, Chi, Haijun, Zhang, Zhiqiang
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 18.12.2019; Wiley Subscription Services, Inc
• Subjects: Bond energy; Charge transfer; Chemistry; Chemistry, Multidisciplinary; Detection; Energy charge; Energy transfer; Ethers; Fluorescence; Fluorescent indicators; imaging agents; peroxides; Peroxynitrite; Physical Sciences; Probes; Pyrene; Red shift; Science & Technology; Strategy; through-bond interactions; CU2; DESIGN; bond energy; FLUORIDE IONS; TRANSFER CASSETTES; imaging agents; peroxides; charge transfer; through-bond interactions; CHEMOSENSOR; HOC1; TBET; HG2+ IONS; SELECTIVE DETECTION; LIVING CELLS
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201903880

A general strategy is reported for developing through‐bond energy transfer (TBET) fluorescence probes by combining intramolecular charge transfer (ICT). The strategy uses a coplanar donor‐π‐bridge‐acceptor system (SiOPh‐PyOH) without spirolactam. The off‐on switch of TBET and ICT is controlled by coplanar structure changes in the sensing process instead of spirolactam ring‐opening in traditional TBET probes. DFT calculations showed that the energy and charge transfers from SiOPh to PyOH are prohibited. Since the SiOPh has no fluorescence, the probe SiOPh‐PyOH shows fluorescence properties similar to that of pyrene. After sensing ONOO−, the silyl ether is removed and the probe changes into −OPh‐PyO−. Electron‐donating ICT from <M‐>OPh to PyO− induces a large redshift of emission to 594 nm (179 nm shift). TBET from <M‐>OPh to PyO− ensures the probe exhibits a large pseudo‐Stokes shift of 213 nm. Furthermore, the probe was successfully used in endogenous ONOO− detection. This study offers a new strategy for the construction of TBET probes emitting in the red region without spirolactam ring‐opening, a new ONOO− sensing system using silyl ether as a reaction site, and a method for the deprotection of silyl ethers with ONOOH under mild conditions. Sensing change: A probe has been developed that provides: 1) a general design strategy for TBET probes; 2) a mechanism of silyl ether cleavage by ONOOH; and 3) a TBET fluorescence probe design based on only one fluorophore for endogenous ONOO−. The probe shows high selectivity, large pseudo‐Stokes shift (213 nm) and large emission shift (179 nm shift; see scheme).