| This paper consists of three parts.In chapter one of this paper, several new different ultramicroelectrodes were fabricated by different methods and were characterized by scanning elechemical microscopy (SECM), Optical Microscope and Cyclic Voltammetry. The result was that their performance was good and they all could be used as the probe of SECM.In chapter two, two new methods for GOx micrometer dots fabrication on the platinum substrate electrode with two microelectrodes fabricated by us by SECM were developed. In the first method, a concave platinum micrometer electrode that fabricated by means of phenol-allylphenol copolymer insulation and electrochemical etching was used in the fabrication of GOx micrometer dots on the platinum substrate electrode. First, the electrodepositon of GOx on the platinum electode was achieved by electrochemical method. In the experiment, we found that when the concentration of GOx was 10 mg/mL, the concentration of Triton X-100 was 0.8 mmol/L, the electrodeposition potential on the Pt electrode was +1.3 V (vs. Ag/AgCl), and the electrodeposition time was 60 min, GOx could be electrodeposited on the electrode best. Then the micrometer dots of GOx were achieved by electrodeposition in this condition with a concave micrometer platinum electrode. In this systerm, the concave Pt micrometer electrode was used both as reference and counter electrode and the substrate Pt electode was used as work electrode. The micropatterns were characterized by both scanning eletron microscope (SEM) and SECM. And we concluded that the diameter of the micropatterns fabricated by this method was about 20 μm. In the second one, GOx micropatterns were fabricated by SECM "Dip-pen" technique with a dual micrometer platinum electrode (DMPE). The principle of this method was that the elements of "Dip-Pen nanolithography" (DPN) of AFM was utilized in SECM. In this work, GOx was first electrodeposited on one platinum electrode of the DMPE in the condition that had been selected in the first method. After the DMPE was placed upon the substrate platinum work electrode, the microelectrode without GOx was used both as reference and counter electrode, the microelectrode with GOx was used as work electrode, and the substrate platinum electrode was used as another work electrode. Appropriate potentials were applied on the two work electrodes, then GOx was desorbed from the microelectrode and deposited on the substrate platinum electrode at the same time. So the activated patterns were fabricated in the process of electrodeposition - desorption -electrodeposition, and the patterns were characterized by SECM.In chapter three, a new method for gold deposition by SECM with micropipet electrode was developed. In this work, a micropipet electrode filled with electrolyte consisted of KAu(CN)2, KF, NaNO3 and a carbon fiber microelectrode used as work electrode, Pt electrode used as counter electrode, Ag/AgCl electrode used as reference electrode in it was used as the probe of SECM. Then a silicon substrate treated with hydrofluoric acid was mounted in a cell and the micropipet electrode moved down toward the substrate. A potential of +1.5V vs Ag/AgCl was applied to the carbon fiber microelectrode and the protons were generated at the micropipet tip by oxidizing nitrite ions. With transfering of electrolyte from across the tip of the micropipet, the protons flowed onto the surface of the silicon substrate and induced the redox reaction between Au(CN)2- and silicon. Si was oxidized to SiF62-, at the same time, the Au(CN)2- was metallized by taking the electrons released from Si. In this method, that micropipet was used as a vessel which contained a lot of molecules desolved the problem of limited molecules in DPN method. With this method, the micropatterns of gold such as micrometer dots, micrometer lines etc were both fabricated and characterized.
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