Application Of β-cyclodextrin Fluorescence Enhancement Method In Chemical Analysis

As the main indispensable part of the supramolecular, the cyclodextrin（CD） been studied more andmore in recent years. Due to the structure with hydrophile exterior and hydrophobic central cavity,β-cyclodextrin（β-CD）can selectively bind different guest molecules to form inclusion complexes in orderto change physico-chemical properties of the guest molecules such as solubility, stability, spectral and soon, so β-cyclodextrin has been widely applied in many fields.In order to improve the analysis determination of detection limit, sensitivity and accuracy, the presentpaper studied β-Cyclodextrin fluorescence enhancement method in the application of chemical analysisdetermination according to the theory of supermolecular chemistry. The mechanism and the influencefactors of β-cyclodextrin fluorescence enhancement have been studied by using UV–vis, fluorescence,infrared spectroscopy.Additionaly, molecular modeling has been carried out to validate the result of theexperiment.The major conclusions can be summarized as follows：1、A new simple, rapid fluorescence method was proposed for the determination of amlodipine(ADB).The method was based on the enhancement of ADB on the fluorescence intensity of the product yielded inthe redox reaction between KMnO4and Methylene blue (MB) in0.20mol·L-1H2SO4medium, in whichβ-CD acted as sensitizing effect reagent. Through an indirect way, the ADB could be determined bymeasuring the fluorescence intensity of the MB. Its maximum excitation wavelength was660nm, and themaximum emission wavelength was678nm. The linear range, detection limit and relative standarddeviation were0.05～3.8mg·L-1,0.005mg·L-1and1.8%, respectively. The method has been successfullyapplied to the assay of ADB in pharmaceutical formulations with satisfactory results.2、Glucose can directly reacted with MB to result in fluorescence quenching in alkaline medium. Ifusing β-CD—MB as a fluorescent probe,the fluorescence intensity of the system was greatly improved. Inthis way, the sensitivity of the method can be improved greatly. Through an indirect way, a new method forthe determination of glucose directly usingβ-CD—MB as a fluorescent probe was established in this article.Its maximum excitation wavelength was660nm, and the maximum emission wavelength was678nm. The linear range and detection limit were0.02～26mg·L-1,0.002mg·L-1respectively. This method can directlybe used for the determination of glucose in real samples.3、A series of inclusion complexes with MB and β-CD were synthesized and studied by UV-Vis andfluorescence spectrometry. The stoichiometric ratio of complexation was confirmed to be1:1. Influencefactors of the different density β-CD, pH,ionic strength and solvents on the inclusion of MB and β-CDwere examined. Additionaly, molecular modeling and infrared spectrum had been carried out whichprovided detailed insights regarding the encapsulation process.4、The Alizarin Violet (AV) and β-CD could form inclusion complex. At pH10、11、12，The AVformed inclusion complex by the form of H222R-，H2R-and HR3-， HR3-which were studied by UV-Vis.Influence factors of the different density β-CD, ionic strength and solvents on the inclusion of AV and β-CDwere examined. Meanwhile, the thermodynamic parameters of inclusion reaction ΔG, ΔH and ΔS wereobtained. Additionaly, molecular modeling and infrared spectrum had been carried out which providedetailed insights regarding the encapsulation process, consistent with the experimental results.