The Synthesis And Research Of Fluorescence Probe Based On Benzoyl Hydrazone Group

Benzoyl hydrazone compounds has the good coordination ability with metal ions because of keto- and enol- tautomers in the structures, while exhibiting a great light, electricity, magnetism, and biological activity, which has important research value in the area of biological and medicinal activity, analysis, catalytic, nonlinear optics materials.Lipopolysaccharides(LPS), otherwise termed ‘endotoxins’, are the primary lipid on the surface of Gram-negative bacteria. Moreover, the massive release of LPS from the cell wall of Gram-negative bacteria could activate the innate immune system. Even a small amounts of LPS appear in the bloodstream will causes a intense reaction, affecting the structure and function of organs and cells, changing metabolic functions, raising body temperature. Hence, the accurate determination of the levels of LPS is very important for investigating cellular functions and disease diagnosis.In this paper, five groups containing acylhydrazone fluorescent compounds have been designed and synthesized, and the UV-Vis absorption spectrum and fluorescence emission spectrum of the target compounds have been measured. By comparison, the five fluorescent compounds have highly specific selectivity. Compounds I、IV、V containing coumarin skeleton have highly selectivity recognition on Cu2+ and quench the fluorescence intensity after combining with Cu2+; Compound II has highly selectivity recognition on Al3+ owing to naphthalene and enhance the fluorescence intensity after combining with Al3+; benzoyl hydrazones III containing quinoline has highly selectivity recognition on Zn2+ and enhance the fluorescence intensity after combining with Zn2+.The compound I、II、IIIcombined with metal ions form complexes, found that the fluorescence intensity were recovered after adding lipopolysaccharide(LPS) to the system by emission spectra. By bacterial experiment, added the same concentration of complex I- Cu2+ to bacteria, under UV light(365nm) irradiation, we found Gram-negative bacteria make the solution fluorescence intensity enhancement, and Gram-positive bacteria is almost constant, so complex I- Cu2+ could be used to distinguish Gram-positive and Gram-negative bacteria quickly in some degree.