Synthesis And Properties Of Chemical Sensors Containing Acridine Fluorescent Groups

Chiral substances are widely found in a variety of natural products.The basic substances in life activities such as sugars,proteins,amino acids,nucleic acids,etc.are mostly chiral,which play an important role in the biological metabolism.Without the chiral substances,the life activities will not be possible.The study of chiral recognition not only helps to understand the phenomenon of life,but also plays an important role in the development of environmental,biological sciences,pharmacy,medicine and supramolecular chemistry.Therefore,the design,synthesis and application of the sensor based on chiral recognition attract the attention of many scientists.Among them,the chiral fluorescence chemosensor with its high efficiency,fast,high sensitivity,low cost and other advantages favored.With the development of industry,environmental problems are becoming more and more serious.The pollution of heavy metal ion has become one of the causes of environmental problems.The normal operation of metabolism need a variety of metal ions.The metal ions which maintain the appropriate content play an important role in the life process.Fluorescence chemosensor which fluoresce as a reflect of specific combination between the subject and objece,can achieve qualitative and quantitative detection of metal ions.As the advantages of short response time,high sensitivity,simple use and low cost,fluorescence chemosensor has attracted much attention in the fields of environmental testing,water treatment and biology.It has been found that compounds with "clamped" arms formed by atoms which include solitary electrons,such as oxygen atoms,nitrogen atoms or sulfur atoms,have special structural characteristics.These compounds contain a special cavity which contain lone pairs of electrons that are capable of interacting with metal ions and chiral anions,causing the interest of supramolecular workers.The introduction of fluorescent groups in such compounds can produce special photochemical properties during the recognition process.In this paper,chemosensors containing acridine fluorophores were designed and synthesized.The interaction and fluorescence sensing properties between these sensors and some common chiral anions?malic acid anions,phenylalanine anions,tartrate anion,alanine anion,etc.?and common metal ions(Mg²⁺,Ca²⁺,Fe²⁺,Co²⁺,Ni²⁺,Cd²⁺,Cu²⁺,Zn²⁺,Mn²⁺,Ba²⁺,Pb²⁺,Hg²⁺,Al³⁺,Fe³⁺,etc.)were studied by UV spectroscopy,fluorescence spectroscopy,mass spectrometry and other methods.The paper is divided into four chapters,the main contents are as follows:?1?The research progress of chiral anion recognition and metal ion recognition,and related fluorescence chemosensors is briefly introduced.Given this background,the design idea of this paper is put forward.?2?Two chiral fluorescence chemosensors?L-1 and D-1?based on acridine were synthesized and their ability to selectively identify chiral anions was investigated by fluorescence spectroscopy,¹H NMR and quantum chemistry calculations.L-1 had a good recognition effect on L-tartaric acid anion and was not effective for D-tartaric acid anion recognition.The 1:1 complex between the subject and the object was determined by the Job curve.The fluorescence response of L-1 and D-1 to tartaric acid anions was different,indicating that they had a good enantioselectivity for tartaric acid anions.In addition,the possible binding mode of L-1 and tartaric acid anions was proposed by ¹H NMR experiment.?3?Two acridine-based fluorescence chemosensors?L-3 and L-4?were synthesized.Their selectivity to metal ions was investigated by IR,fluorescence and cell imaging.L-3 had a significant recognition effect on Fe³⁺,and L-4 had a good selectivity for Ni²⁺.The 1:1 complex between the subject and the object was estimated by the Job curve and the Benesi-Hildebrand equation.The recognition effect of L-3 and L-4 in Hela cells was studied by cell imaging.The results showed that they showed good recognition effect under physiological conditions,which indicated that the fluorescence chemosensors L-3and L-4 had broad application prospects.?4?Two compounds?L-5 and L-6?containing acridine fluorophores were synthesized.The selectivity to metal ions was investigated by fluorescence spectroscopy,cell imaging and ¹H NMR titration experiments.The results showed that L-5 and L-6 could recognize Al³⁺ under physiological conditions and they formed a 1:1 complex with Al³⁺.They did not form corresponding complexes with other metal ions.L-5 and L-6 also showed effective recognition of Al³⁺ in Hela cells.This showed that L-5 and L-6 were fluorescent chemosensors with application value.