An imine bond-based fluorescent covalent organic framework for efficient detection of mercury (II) ions in Camellia oleifera

Camellia oleifera is one of the important woody oil crops in China, and its food safety has attracted much attention. Mercury (Hg) is a highly toxic heavy metal ion, which can enter Camellia oleifera and its products through environmental migration and bioaccumulation, and poses a potential threat to human health. In this study, an imine-linked three-component covalent organic framework (TD-COF) was synthesized by Schiff base reaction from 4,4′,4″-(1,3,5-triazine-2,4,6-triyl) tris (TZ), 2,5-dimethoxyterephthalaldehyde (DM), and 2,5-dihydroxy-1,4-benzenedicarboxylic aldehyde (DA). TD-COF features a rapid and highly sensitive detection of Hg 2+ with a detection limit of 8.43 nM. In actual Camellia oleifera samples, it demonstrated excellent recovery (96.3%–102.54%) and stability. It shows excellent potential for designed imine-linked fluorescent COFs in Camellia oleifera detection.