Design And Synthesis Of Dual-excitation Fluorescent Probe,Tb³⁺-dtpa-bis?fluorescein?,and Application In Detection Of Hydrazine In Environmental Water Samples

Human beings can not leave the living environment that we live on.Human and environment interact with each other.Therefore,the internal relationship between the human body and the natural environment is very close.In recent years,with the development of industry,the variety of organic matter in the environment has become gradually increased,the range of sources also exists in all walks of life,and almost all chemical substances are toxic.It is worth noting that most of them are difficult to be degraded in nature,and when the concentration of this substance is harmful to human beings,it will cause irreversible serious damage to people.Therefore,it is significant to detect and prevent organic pollutants by superior detection methods.Hydrazine?N₂H₄?,as an organic small molecule compound,has a vital important application in chemical industry,medicine,agriculture and so on.It is an important chemical raw material.Hydrazine is also a common high-energy fuel and can be used as rocket propellant.Although hydrazine is of great application value,it proved to be quite toxic,and has also recognized as a potentially carcinogenic toxic substance.Exposure to hydrazine in long term will cause fatal damage to the liver,kidney and central nervous system.Therefore,developing a new detection method of hydrazine with good characteristics has attracted wide attention.So far,various analytical techniques have been developed,such as electrochemical analysis,voltammetry,titration,chromatography and so on,but the fluorescence probe technology has attracted the interest of many researchers for its sensitivity and convenience.In this view,a dual-excitation fluorescent probe has been designed and synthesized in this paper,and the spectral properties and response mechanism of hydrazine have been explored.An improved experimental method was used to synthesize a kind of amino polycarboxylic acid compound ligand DTPA-bis?fluorescein?,forming a terbium complex Tb³⁺-dtpa-bis?fluorescein?with terbium rare earth metal ion,which is used as a dual-excitation fluorescence probe to detect hydrazine.The probe can realize hydrazine detection under the excitation of two excitation wavelengths.In this paper,amino polycarboxylate ligands were first synthesized by esterification between fluorescein and dtpaa.Under the excitation wavelength of 247 nm and 500 nm,hydrazine was used as the analytic targeta of Tb³⁺-dtpa-bis?fluorescein?dual-excitation fluorescence probe.In order to verify the specificity of the terbium complex as a dual excited fluorescence probe,a series of small molecular substances coexisted with hydrazine were selected as interfering substances.Tb³⁺-dtpa-bis?fluorescein?complex as a double excited fluorescence probe for the detection of hydrazine and its detection mechanism is the focus of this research.We also studied the effect of the change of the concentration of hydrazine on the fluorescence spectra of Tb³⁺-dtpa-bis?fluorescein?complex as a dual excited fluorescence probe.At the same time,we also studied the interference of common interfering substances on the detection and analysis of hydrazine at double excitation wavelengths,and found that they did not interfere with the detection and analysis of hydrazine.Through the description of the above experiments,we predict and analyze the reaction process and mechanism of the detection of hydrazine by Tb³⁺-dtpa-bis?fluorescein?as a dual-excitation fluorescence probe.In addition,we have also determined hydrazine in the real water samples,and found that Tb³⁺-dtpa-bis?fluorescein?complex can be used as a dual-excitation fluorescence probe to detect hydrazine in real water samples.It is of great significance for the analysis of the hydrazine in the environment and in the organism.Therefore,it is very important to find a new fluorescent probe with superior detection performance for the detection of hydrazine.