Two-photon fluorescence microscopy has become an indispensable technique for cellular imaging. Whereas most two-photon fluorescent probes rely on well-known fluorophores, here we report a new fluorophore for bioimaging, namely azulene. A chemodosimeter, comprising a boronate ester receptor motif conjugated to an appropriately substituted azulene, is shown to be an effective two-photon fluorescent probe for reactive oxygen species, showing good cell penetration, high selectivity for peroxynitrite, no cytotoxicity, and excellent photostability.
Bibliographical noteFunding Information:
We are grateful for Ph.D. funding to C.M.L.-A. from the EU Horizon 2020 research and innovation program under Grant Agreement H2020-MSCA-CO-FUND, No. 665992. We thank the Center for Doctoral Training in Sustainable Chemical Technologies for Ph.D. funding to M.W. under EPSRC Grant EP/L016354/1. We also thank EPSRC for DTP Ph.D. funding to L.C.M. H.M.K. acknowledges a grant from the National Leading Research Lab Program of the National Research Foundation of Korea (NRF), funded by the Korean government (MSIP; No. 2016R1E1A1A02920873). In addition, T.D.J. wishes to thank the Royal Society for a Wolfson Research Merit Award and for funding to F.P.-C. under Grant CHGR1170010. This work was supported by a seed corn grant from the CR@B (Cancer Research at Bath) network. The British-Spanish Society and Plastic Energy are thanked for a 2017 Scholarship to C. M. L.-A. This research made use of the Balena High Performance Computing (HPC) Service at the University of Bath. NMR, X-ray crystallography, and MS facilities were provided through the Materials and Chemical Characterisation Facility (MC 2 ) at the University of Bath. We thank Prof. Uwe Pischel and Prof. Thorfinnur Gunnlaugsson for helpful discussions.
© 2019 American Chemical Society.