Research And Application Of Cucurbituril Electrochemical Sensor In Drug And Food Analysis

Cucurbituril as the 4th generation supramolecular host compound,because of its special structure,hydrophobic cavity,hydrophilic port and rigid plane structure,cucurbituride will form a stable inclusion compound when interacting with the guest molecule supramolecular,and the conformation will not be reversed.Therefore,host-guest recognition of cucurbituril and guest molecules has been widely used in drug analysis,chromatographic analysis,biosensor,food and environmental sample analysis,etc.In recent years,many researchers have paid more attention to it.In this paper,a new cucurbit[7]uril?CB[7]?electrochemical sensor was established by cyclic voltammetry using supramolecular host and guest recognition.Differential pulse voltammetry was used to detect dopamine and ascorbic acid accurately and quickly.This paper studies the following parts:1.The development of supramolecular chemistry is briefly described,and the supramolecular interaction between cucurbituril and guest molecules,the structure,synthesis and practical application of cucurbituril are summarized.The present situation of the application of cucurbituril in electrochemistry is described,and the purpose and content of this paper are described.2.Cucuribit[7]uril-graphene modified electrode was prepared as working electrode.The electrode modified by CB[7]-GO was characterized by electrochemical impedance spectroscopy.The dopamine was detected by cyclic voltammetry.After the optimization of the experimental conditions,the pH value of dopamine was 7.0 and the scanning speed was0.1V/s,in the concentration range of 2×10^-48×10^-3mol/L,there was a good linearity with the oxidation peak current and the reduction peak current.In human plasma samples,the dopamine was determined by standard addition method,the recoveries in actual samples reached 97.6%¹01.1%.3.Ascorbic acid was determined by the modified cucuribit[7]uril electrode,and the peak current of ascorbic acid was obviously changed by cyclic voltammetry,the redox peak current changed with the change of experimental conditions.By differential pulse voltammetry,the electrode has good linear range,low detection limit and high sensitivity when it is used for the determination of ascorbic acid at different pH and different concentrations.The method has been applied to the determination of ascorbic acid in orange juice and Jinsherkang multi-dimensional element tablets with satisfactory results.An accurate,rapid and sensitive electrochemical method for the determination of ascorbic acid has been established.4.In addition,the magnetic microspheres modified by cucuribit[6]uril?CB[6]?were preliminarily investigated and applied to the determination of tetracaine hydrochloride?TCH?in human plasma.Some parameters affecting the extraction rate,including pH of solution,amount of extractant,desorption agent,analytical volume,extraction and desorption time,were studied experimentally.Under the optimum conditions,the linear relationship of this method is good in the range of 0.2-2?g mL^-1of TCH concentration.The correlation coefficient R²is 0.9992,and the linear equation is y=0.688x+0.034.The detection limit of this method is 0.4?g mL^-1.The percent recovery of standard plasma sample reached 95.78¹01.65%.