Single Cell Electrochemical Control Technology Based On Manganese Dioxide Microelectrode Array

Single-cell analysis is an important technical means to study life processes at the cell and subcellular levels.However at present,single-cell analysis technology is often affected by the purity,missed selection,fault selection and cell manipulation of the subcellular technology,resulting in a decrease in the accuracy of single-cell analysis.Therefore,the development of new single-cell sub-selection control technology is very important for single-cell analysis.With the development of nanotechnology and micro-processing technology,single-cell control system based on microflow control system and microelectrectror array has developed rapidly in recent years.This technology has many advantages,including small sample demand,simple handling,short control response time and high selection accuracy.Based on the nanostructure of manganese dioxide,the electrochemical system of microelectrode array was constructed by using ultraviolet photolithography microfabrication technology.The cell adsorption antibody was modified on the surface of manganese dioxide to achieve the capture of the target single cell.By electrochemical etching of the target microelectrode through electrochemical etching,and cuttings off the connection between the microelectrorectrometer and the target single cell,the release and manipulation of the single cell were achieved.The main results of this thesis are as follows:(1)At first,the electrode array was prepared by deposition of gold on the glass substrates by using the magnetically controlled sputtering and extreme ultraviolet lithography microfabrication technology.Then,manganese dioxide microelectrode are assembled in the core electrode region by using the UV photolithography technology and the self-assembly of manganese dioxide nano-hollow spheres.Through optical microscope and scanning electron microscope observation,it was found that the prepared manganese dioxide / gold microelectrode array was basically in agreement with the device design.The total size of the manganese dioxide-gold composite microelectrode array is 40mm×40mm square,the core electrode size is 120mm×120mm square electrode,and the distance between the electrode is1080mm,There are total 88 electrodes and 88 foot electrodes on the array.(2)By observing the changes of the circular voltage-current curve and the corresponding etching effect of manganese dioxide microelectrodes,the relationship between manganese dioxide microelectrode capacitance and etching effect is constructed.Changes in the thickness of manganese dioxide film before and after etching was characterized by using atomic force microscope(AFM).Then,under different parameters like scanning rate,electrode spacing and electrochemical window,the capacitance change of the electrode before and after the etching was tested.the increase of the scanning rate,the decrease of the electrode spacing,and the widening of the electrochemical window can strengthen the electrochemical etching of the manganese dioxide.(3)Using Ep-CAM modified manganese dioxide microelectrode to capture circulating tumor cells,it was demonstrated that 32% of the single electrode units in the manganese dioxide microelectrode array can capture a single target cell.Treating with 1.0V voltage enables the electrochemical etching of a single manganese dioxide microelectrode,and thus the cut off of the connection between microelectrode and single cells,resulting the release of a single target cell.In summary,the microelectrode array based on manganese dioxide is constructed and applied to the capture and release of single cells by electrochemical method.It was demonstrated that the manganese dioxide-based microelectrode array single-cell control system can be used for single-cell sorting of circulating tumor cells.This technique is expected to provide a new single-cell sorting control platform,which can be in combination with singlecell analysis system,for single-cell research of multiple cells.