Opening a Gateway for Chemiluminescence Cell Imaging:Distinctive Methodology for Design of Bright Chemiluminescent DioxetaneProbes

摘要

Chemiluminescence probes are considered to be among the most sensitive diagnostic tools that provide high signal-to-noise ratio for various applications such as DNA detection and immunoassays. We have developed a new molecular methodology to design and foresee light-emission properties of turn-ON chemiluminescence dioxetane probes suitable for use under physiological conditions. The methodology is based on incorporation of a substituent on the benzoate species obtained during the chemiexcitation pathway of Schaap’s adamantylidene–dioxetane probe. The substituent effect was initially evaluated on the fluorescence emission generated by the benzoate species and then on the chemiluminescence of the dioxetane luminophores. A striking substituent effect on the chemiluminescence efficiency of the probes was obtained when acrylate and acrylonitrile electron-withdrawing groups were installed. The chemiluminescence quantum yield of the best probe was more than 3 orders of magnitude higher than that of a standard, commercially available adamantylidene–dioxetane probe. These are the most powerfulchemiluminescence dioxetane probes synthesized to date that are suitablefor use under aqueous conditions. One of our probes was capable ofproviding high-quality chemiluminescence cell images based on endogenousactivity of β-galactosidase. This is the first demonstrationof cell imaging achieved by a non-luciferin small-molecule probe withdirect chemiluminescence mode of emission. We anticipate that thestrategy presented here will lead to development of efficient chemiluminescenceprobes for various applications in the field of sensing and imaging.