Selective Phosphate Fluorescence Detection Over Pyrophosphate in Aqueous Media With a Cerium‐Based Chemosensor

Phosphate ions are important molecules playing essential roles in biological and agricultural processes. Although numerous phosphate sensors have been reported, selective detection under physiological conditions and in complex media remains challenging. Over the past decades, several strategies have been developed to address this challenge, including the design of sophisticated receptors, but with limited success. Herein, using readily accessible chemicals, we report a straightforward metal extrusion‐based fluorescence indicator displacement assay (MEFID) for the detection of phosphate. By combining a commercially available fluorophore and cerium ammonium nitrate (CAN), phosphate ions in aqueous solutions were successfully detected. We demonstrate that this inorganic complex detects phosphate ions at low micromolar concentrations, either spectrophotometrically or with the naked eye, with high selectivity over common competing anions including halides, acetates, carbonates, and remarkably, pyrophosphate. In addition, interference of the sensor with phosphorylated molecules appears to be minimal, thus providing a cost‐effective and efficient chemosensor for phosphate over pyrophosphate.