Study And Application Of The New Chemically Modified Electrodes And Biosensors

The chemically modified electrodes have been a most burgeoning and one of the most flourish research realms in the electrochemistry and electroanalytic chemistry since it was developed in the middle of 70's . It was for the moment widely applied in many cases such as life sciences , environmental science , analytic science and material science . The mediators modified on the surfaces of electrodes can realize the electrocatalytic reactions by accelerating electron transferring between redox centers and the electrode surface . The carriers immobilizing the mediators have a great influence on the electrochemistry activities of the mediators , The electrocatalysis of the modified electrodes is an enormous impetus for its development and was widely used in the slow electron transferring processes which isn't easily realized , for example . the electrocatalysis of biomolecules , organic compounds and inorganic ions.Recently the study of chemical modified electrode ( CME ) which act as electrochemical sensor was very plentiful. The chemical modified carbon paste electrode (CMCPE) which was fabricated by mingling modifier with carbon paste applied more often. The CPE has the characteristics of easily modified, wide using range, fabricated easily, innocuity, long life span etc. Because modified special substance CMCPE has special function, it is studied more and more by electrochemical worker now. Supermolecule chemistry, the emerging and up-to date cross subject, involves all subjects of chemistry biochemistry and material science etc. In that supramolecule chemistry chemistry offers an effective method for chemists to solve the long-term puzzle of improving selectivity, it has gotten a great development from it's theory being put forward. We can expect the greatly wide application of supermolecule chemistry on CME. But because the difficulty how to station it on the surface of electrode cannot be solved easily, the application of supermolecule chemistry on CME was defined. And its usage on CMCPE was further less.Two organic reagents were used as modifier in the fabrication of CMCPE bonded with paraffin in our research. First, A l-(2-Pyridylazo)-2-naphthol modified carbon paste electrode was fabricated and a differential pulse cathodic voltammetric method was developed for the sensitive and selective determination of Ni (II). Second, The solid paraffin wax carbon paste electrode was modified by the complex of dithizone with β -CyClodextrin crossing-linking polymer. The electrode was used to determine Cd2+ with anodic stripping voltammetry method. The electrode was found to decrease the solubility of Dithizone in alkalescence solution and effectively minish the lose of deoxidize state of metal.The construction of glucose biosensor by immobilization of glucose oxidase(GOD) on the surface of Au and Ag2O nanoparticles is reported, and polyvinyl butyral(PVB) is used as auxiliary immobilization enzyme matrix. The experiments show that the nanoparticle would have a wery strong enhancement effect on the GOD electrode response sensitivity. The data of the current response of enzyme electrodes containing hydrophilic Au and Ag2O nanoparticles to glucose are obtained. A mechanism for the behavior of nanaoparticles in immobilization enzyme. This report provides experimental and theoretical basis for preparing the useful glucose biosensor.