Preparation Of Fluorescent Carbon Dots And Its Application In Ion Detection

With the continuous growth of nanoscience and nanotechnology,the development of nanomaterials science is flourishing,and many new types of nanomaterials have been discovered.So far,the synthesis route of nanomaterials have become increasing perfect.People can make use of different methods to synthesize complex nanocomposites.The mature characterization means uncovered the mysterious veil of the unique physicochemical properties of nanomaterials,and the wide application prospects have made the importance of nanomaterials increasingly prominent.As a new type of fluorescent carbon nanomaterials,carbon dots not only inherit good biocompatibility of carbon nanomaterials,but also possess excellent fluorescence properties.Its unique physical and chemical properties make it become a rookie of fluorescent nanomaterials after it is discovered,and has good application prospect in the fields of biosensing,nanomedicine and photoelectrocatalysis.Fluorescent probes are a kind of special fluorescent molecules,which can change their own fluorescent properties sensitively and specifically according to the changes of the external environment.With the in-depth study of carbon dots,carbon dots are used as a fluorescent probe to build biosensors in the field of analytical testing promising.This dissertation focuses on carbon dots in the following three aspects: preparation,characterization and application.The carbon dots and biosensors combined and applied to the detection of heavy metal ions,mainly including the following:(1)Using wolfberry as carbon source,carbon dots were prepared by hydrothermal method and applied to the trace analysis of Fe3+.The synthesis conditions were optimized.The morphology and properties of carbon dots were characterized by high resolution transmission electron microscopy,X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.The optical properties and biocompatibility of the prepared carbon dots were also explored.Because of its excellent fluorescence properties,it is used as a fluorescent probe for Fe3+detection.The results show that the carbon dots have excellent selectivity,high sensitivity and good stability to Fe3+.Therefore,a simple and rapid method for the determination of Fe3+ was established.(2)Solvothermal method was used to synthesize nitrogen and chlorine co-doped carbon dots by N-Chlorosuccinimide as carbon source.The influence factors in the preparation process were studied and the stability of the fluorescence properties was explored.The microstructure and surface functional group composition of carbon dots were investigated,and their fluorescenceproperties and cytotoxicity were studied.The use of heavy metal ions on the carbon fluorescence quenching effect,successfully applied to Ag+ detection.