Recent Advances and Challenges in Luminescent Imaging: Bright Outlook for Chemiluminescence of Dioxetanes in Water.

Chemiluminescence is gradually being recognized as a powerful tool for sensing and imaging. Most known light-emitting compounds undergo chemiexcitation through spontaneous decomposition of cyclic peroxide moieties. A ground-breaking milestone in the chemistry of such compounds was achieved 30 years ago with the discovery of triggerable dioxetanes by Schaap's group. Our group has recently developed a distinct methodology to significantly improve the light emission efficiency of such phenoxy-dioxetane luminophores under physiological conditions. Introduction of an electron-withdrawing substituent at the ortho position of the phenoxy-dioxetane resulted in an approximately 3000-fold increase of the chemiluminescence quantum yield in aqueous media. Furthermore, we discovered that the emission wavelength and the kinetics of the chemiexcitation could be determined by the electronic nature of the substituent incorporated on the dioxetane luminophore. This recent development has provided scientists with new powerful chemiluminophores that can act as single-component probes for in vivo and in vitro detection and imaging of various analytes and enzymes. This outlook describes the recent progress toward applications of synthetic chemiluminescence luminophores suitable for sensing and imaging in aqueous environments.