Synthesis Of Cyclodextrin Derivatives And Their Application In Electrochemical Detection

Cyclodextrin,as a kind of cyclic oligosaccharide molecule with hydrophobic inner cavity and hydrophilic outer cavity,can bind a variety of guest molecules in aqueous solution to form supramolecular complexes,which has broad application prospects in many fields.Therefore,cyclodextrin chemistry has become one of the frontier areas of today.In particular,modification of the natural cyclodextrin with various versatile groups could widen the application scope by overcoming some drawbacks,such as molecular recognition selectivity,good solubility,providing optical probe absence,and so on.In this thesis,several functional groups were used to modify natural cyclodextrin to obtain several novel cyclodextrin derivatives.Furthermore,the cyclodextrin derivative was used as building block to construct the functional gold nanoparticles,and their electrochemical sensor performances were investigated by means of electrochemical experiments.The contents are divided into the following parts:1.Per-[6-deoxy-6-chloro]-?-cyclodextrin and per-[6-deoxy-6-bromo]-?-cyclodextrin were synthesized by Appel-Lee reaction.Then they are used as intermediate products to undergo nucleophilic reaction with ethylenediamine,mercapto acetic acid,3-mercaptopropionic acid and p-hydroxybenzaldehyde to synthetize substituted cyclodextrin derivatives,including per-[6-deoxy-6-ethylenediamine]-?-cyclodextrin,per-6-deoxy-per-6-(2-carboxy-methyl)thio-?-cyclodextrin sodium salt,per-6-deoxy-per-6-(2-carboxy-ethyl)thio-?-cyclodextrin sodium salt,per-6-deoxy-per-6-(2-carboxy-methyl)thio-?-cyclodextrin potassium salt,per-6-Perdeoxy-6-(4-formyl-phenyl)]-?-cyclodextrin.These compounds were characterized by means of 1H-NMR,MS and FTIR.2.The compound,per-6-deoxy-per-6-(2-carboxy-methyl)thio-?-cyclodextrin sodium salt(CT),was selected to synthesized gold nanoparticles(CT/AuNPs)according to the experimental result of all the modified-cyclodextrins gold nanoparticles,then,CT/AuNPs were loaded onto activated carbon(AC)to prepare a novel electrode material.The morphology of the electrode material was characterized by scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The electrochemical performances were characterized by cyclic voltammetry and electrochemical impedance spectroscopy.3.The cyclodextrin-modified gold nanoparticles loaded activated carbon(AC/CT/AuNPs)were modified as electrode materials to the surface of the glassy carbon electrode to obtain a novel modified electrode.Moreover,electrochemical sensing experiments such as cyclic voltammetry and differential pulse voltammetry were used to investigate the sensing performance of the modified electrode on p-nitrophenol(p-NP),and the advantages of wide linear range and high sensitivity were revealed.Electrochemical sensors have advantages,such as the advantages of ?-cyclodextrin derivatives with electrocatalytic activity,rapid electron transfer and supramolecular recognition.