An activatable natural chalcone-based luminescent rotor for visualized screening of viscosity fluctuation in liquids

Abstract

The viscosity of a liquid is a critical parameter of its quality, and is closely linked to the onset of the spoilt stage of the liquid. Herein, the molecular rotor Hcc, extracted from the natural plant F. eucommiae, was used to detect viscosity changes in liquids. Hcc, made of aromatic ketone and phenol moieties, formed a typical twisted intramolecular charge-transfer (TICT) conformation. This rotor demonstrated high sensitivity, selectivity, photostability, universality, and a large Stokes shift, enabling the precise analysis of changes in viscosity during the liquid spoilage process. Its fluorescence intensity was proven to be highly dependent on the degree of liquid corruption. Hcc can serve as a novel tool for food quality control applications.