A Turn‐On Fluorescence Probe Based on a New Salamo‐Co (II) Coordination Polymer for Tyrosine Detection and Its Application in Water Samples

ABSTRACT A novel salamo‐Co (II) coordination polymer probe CP was synthesized firstly, and its crystal structure, [Co 3 (L) 2 (PTA)(H 2 O) 2 ] n ·4nDMF, was determined by X‐ray diffraction analysis. The probe has a rare aggregation‐induced luminescence enhancement (AIEE) effect. When applied to amino acid detection, it was found to have a high selective recognition of tyrosine. With the increase of tyrosine, the fluorescent strength of the probe was enhanced in a short period of time. In addition, the binding ratio of probe to Tyr was determined by fluorescence titration experiment, and the detection limit LOD of probe CP for Tyr was calculated to be 2.57 × 10 −9 M, and the binding constant Ka was 2.96 × 10 5 M −1 . According to UV absorption spectrum, FT‐IR spectra, ESI mass spectrometry, and DFT calculation, it was speculated that Tyr can bind to the probe after adding Tyr into the probe solution, triggering FRET and ICT effects, resulting in increased fluorescence intensity and blue shift, and finally achieving the specific recognition of tyrosine by probe CP . Finally, the practical application of probe CP was studied. Through strip test and real water sample test, it was found that the probe can be used for qualitative and quantitative analysis of tyrosine.