Sub-micron Electrode / Micro-electrolysis Cell With Electrochemical Detection Single Neutrophil Cell Peroxidase

This thesis consists of three parts: In Chapter Ⅰ, dual microelectrodes with tip diameters of <200 μm were made with theta glass capillaries. A gold microelectrode and a Ag/AgCl reference electrode were inserted into the two channels of the theta glass capillary, respectively since the diameters of the microelectrodes were smaller than 200 μm, the microelectrodes could easily be placed into an electrochemical microcell to analyze compounds in the solution. The difficulty in construction of the microelectrodes was integrating the working electrodes and the large reference electrodes into the theta glass capillaries parallelly without any electrical contact between the electrodes. The another difficulty was sealing the theta glass tips, without solution leaking. The dual microelectrodes were characterizated by voltammetry in solution of 1.00×10^-2 mol/L K₃Fe(CN)₆ and 0.500 mol/L KC1, and then were used to determinated BQ.In Chapter Ⅱ, we determinated perexidase (PO) activity in the extracts of human neutrophils using the voltammetry with dual microelectrodes constructructed by the gold microelectode and the Ag/AgCl reference electrode, through detecting the product BQ of the enzyme catalytic reaction.In Chapter Ⅲ, we fabricated electrochemical microcells with volumes of 20 nL-40 nL by etching a microscope glass slide using HF. The dual microelectrodes consisted of a gold working electrode and a Ag/AgCl reference electrode (diameter 100 μ,m) was inserted in the microcell. A single cell was manipulated to the microcell with pushing slide, and lysed with using freezing and melting. Then the enzyme substrates H₂Q and H₂O₂ were injected into the microcell. The PO activity in a single cell was determined by voltammetry.