1O2-Relevant Afterglow Luminescence of Chlorin Nanoparticles for Discriminative Detection and Isotopic Analysis of H2O and D2O

Abstract

Discriminative detection between D2O and H2O is important for diverse fields but challenging due to their high similarity in chemical and physical properties. Current molecular sensors for D2O detection generally rely on the spectral change of fluorophores with suitable pKa in response to D2O and H2O with slightly different pH acidity. Herein, we report a new and facile D2O sensor by using singlet oxygen (1O2)-relevant afterglow luminescence of chlorin e4 nanoparticles (Ce4-NPs) to achieve distinguishable detection between D2O and H2O. As 1O2 is a key initiator involved in the afterglow luminescence process, it displays a 22-fold longer lifetime in D2O relative to H2O and thereafter generates more dioxetane intermediates after laser irradiation to lead to ultimate afterglow brightness of Ce4-NPs in D2O. In addition, Ce4-NPs are capable of quantitatively detecting the amount of H2O in D2O with a limit of detection (LOD) of 1.45%. Together, this study broadens the utility of afterglow materials and presents a facile strategy for isotopic purity analysis of heavy water.