The Preparation And Research Of Detection Properties For Contaminants Based On Fluorescent Nanocomposites

With the development of social economy,science and technology,the process of industrialization and urbanization is also developing rapidly,and the problem of environmental pollution in China is becoming more and more serious,in which organic pollutants and heavy metal pollution have aroused widespread concern.Therefore,it is necessary to detect and control these pollutants.At present,the detection of the above pollutants are still based on traditional methods,such as inductively coupled plasma mass spectrometry,atomic absorption spectrometry,inductively coupled plasma atomic emission spectrometry,X-ray absorption spectrometry,electrochemical analysis,chromatography spectrophotometry,neutron activation analysis,titration and so on.However,these techniques have some shortcomings,such as expensive instruments,time-consuming,complex detection process,and tedious sample preparation by technicians.In recent years,many detection based on fluorescent nanomaterials have attracted wide attention because of their simple design,convenient operation and good stability.In this paper,the preparation,properties and application of carbonized polymer dots and its nanocomposites are discussed.The specific work is as follows:In this paper,firstly,yellow fluorescent carbonized polymer dots with fluorescence enhancement were synthesized by one-step hydrothermal method with o-phenylenediamine as carbon source and ferric chloride as inhibitor.The synthesis method is simple and has excellent stability.As a sensor for the detection of hydrazine hydrate,and it could achieve high selectivity and high sensitivity for hydrazine hydrate.The fluorescence intensity of carbonized polymer dots were proportional to the concentration of hydrazine hydrate,and the detection limit was 0.168 μM.In addition,carbonized polymer dots were introduced into the film system,and polyvinyl alcohol fluorescent film based on carbonized polymer dots was successfully prepared,which expanded its application in rapid and convenient detection of hydrazine hydrate.The above conclusions show that the carbonized polymer dots have excellent fluorescence properties and application prospects.In addition,in order to solve the error caused by the change of the emission peak intensity based on the single excitation wavelength,which is easily affected by the change of the probe concentration in complex samples and the matrix effect,a new type of double emission carbonized polymer dots-copper nanocluster nanocomposite materials was prepared in this chapter.Carbonized polymer dots with negative charge were synthesized by one-step hydrothermal method using bovine serum albumin as carbon source.Meanwhile,copper nanoclusters were prepared by using copper nitrate and L-penicillamine as copper source and stabilizer,respectively.The surface of copper nanoclusters protected by L-penicillamine has strong positive charge,which can be electrostatically assembled with the prepared carbonized polymer dots to form carbonized polymer dots-copper nanocluster nanocomposite materials.The fluorescence color of the prepared nanocomposite materials under UV lamp was pink and the hypersensitivity of mercury ions could be detected.With the increase of mercury ion concentration,the fluorescence color of the carbonized polymer dots-copper nanocluster nanocomposite materials gradually changed from pink to blue.The detection limit of carbonized polymer dots-copper nanocluster nanocomposite materials in aqueous solution was low(0.31 n M).On the other hand,the nanocomposite materials were successfully applied to the detection of mercury ion in real water samples.On this basis,a portable mercury ion rapid detection test paper was also developed,which can increase the practical application of carbonized polymer dots-copper nanocluster nanocomposite materials in food safety,environmental monitoring,biomedical detection and other aspects.