| Carbon quantum dots(CQDs),a new type of nano materials,have been paid more and more attention by researchers.it not only has all the properties the traditional nano materials have,but also has many excellent characteristics,For example,its low cytotoxicity and good biocompatibility make it indispensable in the field of life science.After many years of hard work,the study of fluorescent biomarkers can stride forward.Besides,it is also very important for ion detection and small molecule drug detection,more and more new methods have been established for the quantitative determination of ions and drugs with carbon quantum dots as fluorescent probes.These methods are simpler,faster,and more accurate,and most of them have been applied to the actual sample testing,so we focus on the selection of cheap and easy carbon sources,using the most simple way to synthesize the CQDs,and attempt to analyze the fluorescence properties and apply the CQDs to the detection of ions and drugs are also used to explore the binding mechanism between them.The main contents of this paper include four parts:1.The CQDs were synthesized by microwave with D-maltose and D-fructose as carbon source;The structural characterization,optical properties and potential applications of the synthesized CQDs have been investigated,The results show that the quantum dots prepared by microwave have uniform particle size,good dispersion and excellent fluorescence properties;This kind of carbon quantum dots have good fluorescence properties in weak acidic environment.The surface active agent has little effect on the fluorescence property,and Some redox agents,metal ions have a certain degree of sensitization and quenching effect on the fluorescence intensity.In addition,by the analysis of the structure and the optical properties of the synthesized carbon dots,the internal mechanism is discussed,which lays a good foundation for its application2.Based on the analysis of the structural properties and the fluorescence properties of the synthesized carbon quantum dots in the first part,we selected the D-maltose ascarbon source to synthesize carbon quantum dots,and used the carbon quantum dots as fluorescent probes to detect trace Co2+ in river water.The results show that the carbon quantum dots have higher selectivity for Co2+ compared with other common metal ions.The relative fluorescence intensity and the concentration of Co2+ showed a good linear relationship between 0.03?g/m L~0.6?g/m L and 0.6?g/m L~4?g/m L.The detection limit was 0.00384?g/m L.In addition,the reasons for the quenching of the fluorescence signal of Co2+ are simply explained by the results of several experiments.3.In the citric acid buffer solution of p H=4.80,a new rapid and selective method for the determination of Troxerutin was established by using carbon quantum dots as fluorescent probes.The results showed that when the concentration of Troxerutin in1.0×10-7~3.0×10-5 mol/L range showed good linearity with the fluorescence intensity of CQDs,the detection limit of 4.5×10-9mol/L,discussed the interaction mechanism between them,the conclusion is dynamic quenching.4.In the B-R buffer solution of p H=5.00,a new rapid and selective method for the determination of ranitidine hydrochloride was established by using carbon quantum dots as fluorescent probes.The results showed that when the concentration of ranitidine hydrochloride was 1.0×10-6 ~ 7.0×10-5 mol/L and 1.0×10-7 ~ 1.0×10-6 mol/L,which showed good linearity.The detection limit was 7.1×10-8 mol/L,the content of the sample was determined,and the recovery was 96.41%~99.00%.The quenching mechanism was simply determined by Stern-Volmer equation,temperature and UV spectrum,and the conclusion is dynamic quenching. |
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