Synthesis And Separation Of CQDs And Its Application On Identification Of Nitrophenolisomeride

As a novel fluorescence nano-material Carbon quantum Dots(CQDs) has been paid more attentions in recent years. It has been applied in many fields because of its environmental friendly, better biocompatibility, easy preparation and functionalization. There are many kinds of compounds can be used to prepare CQDs. The main work of this paper are concluded as follow:1. CQDs with blue fluorescence property was synthesized from chitosan via hydrothermal methodunder acidic condition. The structure, morphology and properties of CQDs were characterized by using FTIR, TEM, UV-Vis, FS and NMR analysis. The possible formation mechanism was proposed according to the analysis results of MS. The biocompatibility of CQDs was evaluated by cell hemolysis assay.2. High performance liquid chromatography(HPLC) was used to separate and purify CQDs. The effective chromatographic resolution was obtained under optimal conditions including appropriate stationary phase and suitable composition and flow speed of mobile phase. The possible structure of CQDs separated by HPLC was revealed according to MS analysis. The fluorescence quantum efficiency was also tested.3. The interaction between nitrophenol isomers and CQDs decorated with phenylalanine was researched. The effects of these two isomers on the fluorescence intensity of CQDs were investigated. It is also studied the best condition for identification nitrophenol isomer. The work in this paper indicates that the fluorescence quantum efficiency of CQDs increases greatly after separated by HPLC. It is beneficial for improving fluorescence property of CQDs, which was influenced by complex composition and fluorescence energy resonance. The fluorescence recognition of isomers by using CQDs will play an important role to enlarge the application field of CQDs.