Research On The Design And Analysis Characteristics Of Bipolar Electrode Electrochemiluminescence Detection Device

Bipolar electrode has attracted much more attention because of its simple structure and wirelessly induced electrochemical reaction.It has been widely used in the field of biological analysis,electrochemical reaction mechanism research,material processing and other fields.At present,although the combination of bipolar electrode electrochemiluminescence(ECL)sensing method and microfluidic chip has been widely used,the selection and processing of electrode materials are more complex.Therefore,it is of great significance to develop new bipolar electrode electrochemiluminescence devices and explore new analytical properties.This thesis is consisted of two parts:the review section and the research section.In the review part,the bipolar electrodes and their characteristics are briefly introduced,the recent advances of bipolar electrodes in the field of electroanalytical research is highlighted.The research contents consist of the following two parts:1.The design and analysis of ECL detection device for the microvolume closed gold-based bipolar electrode and its ECL analytical application for miRNA.In this study,a closed gold-based microvolume bipolar electrode was designed and the introducing method of the microvolume sample in this ECL device was investigated.On the basis of this,an ECL device was designed to detect the signal of electroluminescence induced by micro cavity samples.This device can not only realize the sampling of trace samples,but also can avoid the influence of the electrode reaction on the driving electrode on the detection result based on the conductive effect and the static effect of the solution in the capillary,and effectively realizes the electrochemical detection of a few microliters liquid sample in the microcavity.In the specific work,the interaction between gold electrode modified by 1,3-propanedithioland and the interaction between Au-NPs and DNA was used to establish a new method for the determination of trace miRNA by ECL.Under optimal conditions,when the concentration of Let-7a is in the range of 1.0×10-12 to 9.0×10-12 mol·L-1,it shows a good linear relationship with the ECL intensity.The detection limit is 0.3 pmol·L-1.A simple and rapid quantification of miRNA in trace serum samples was achieved.2.The design of the microvolume bipolar ECL cell based on nafion modified glassy carbon microsphere bipolar electrode.In this work,the glassy carbon microspheres(GCBs)were selected as bipolar electrodes and the Nafion film and Ru(bpy)32+ were immobilized on the GCBs to prepare ECL activity GCBs.In order to conveniently and effectively study the ECL characteristics of glassy carbon microspheres,we design a simple,microvolume device.To detect the analytical properties of the device,the Ru(bpy)32+/TPA electrochemiluminescence system were studied.In the range of 1.0×10-7 to 9.0×10-7 mol·L-1,the concentration of TPA showed a good linear relationship with the electrochemiluminescence intensity.The detection limit of TPA was 10 nmol·L-1.The device not only has small sample consumption(about 70 microliters),but also can avoid the influence of the electrode reaction on the driving electrode to the ECL signal in the detection cell.By using this device,we can also detect the single glassy carbon microsphere by the ECL signal.