Preparation,Synthesis And Application Of Fluorescent Probe Molecules Based On Ion Recognition

Some metal cations and anions play an indispensable role in social production and life,but excessive existence will cause environmental pollution,and residues in the human body will also lead to corresponding diseases.The detection and identification of metal ions and anions are therefore of great importance in the fields of environment,biochemistry and health care.In order to achieve this goal,many detection methods have been developed,among which organic fluorescent probes have become the focus of research in recent years as a new detection method with the advantages of high selectivity,high sensitivity,naked-eye recognition and cellular imaging compared to traditional detection methods.In this paper,we designed and synthesized three new organic fluorescent probes for the recognition of CN^-and Zn²⁺using acridin-9-amine,phenothiazine and 8-hydroxyquinoline as raw materials,and demonstrated their structures,fluorescence sensing properties and applications in bioimaging by 1H NMR,ultraviolet absorption spectroscopy,fluorescence emission spectroscopy,linear fitting and cell imaging.The specific work contents are as follows:1.Using acridine-9-amine and 3-nitrophenyl isothiocyanate as raw materials,a fluorescence probe Q1 with high selectivity for CN^-ion recognition was designed and synthesized,and it could effectively recognize CN^-in the presence of other interfering ions.When probe Q1 was combined with CN^-,obvious fluorescence quenching phenomenon occurred,and obvious color change was shown under UV lamp.The fluorescence intensity of the probe gradually decreased with the increase of CN^-ion concentration,showing a linear fitting relationship.The binding ratio between the probe and CN^-was 1:1,and the detection limit was 2.0×10^-7 M^-1.The biocompatibility of probe Q1 was further demonstrated by living cell imaging and biological imaging experiments.2.Another novel fluorescent probe Q2 was designed and synthesized based on phenothiazine and 2-Acetylbenzofuran,which can realize highly selective recognition of CN^-under complex conditions,and realize naked eye recognition under daylight and ultraviolet lamps.A significant reduction in fluorescence was found upon interaction of the probe Q2 with the CN^-ion,and the two bound 1:1 with a binding constant of 5.94×10³ M^-1,and the detection limit was 2.39×10^-7 M^-1.The successful application of probe Q2 to the imaging of hepatocellular carcinoma cells and zebrafish demonstrated its wide application performance.3.A fluorescent probe Q3 was designed and synthesized based on 8-hydroxyquinoline and 2-aminoanthraquinone,which can form a 1:1 complex with Zn²⁺.The probe can recognize Zn²⁺ with high selectivity and sensitivity,and the probe Q3 underwent significant fluorescence enhancement with increasing Zn²⁺concentration,accompanied by a significant colour change.The limit of detection was calculated to be 5.36×10^-6 M^-1.Finally,cell imaging and bioimaging results were observed by fluorescence microscopy to reveal the potential applicability of probe Q3.