Structure Optimization Research Of Nanomaterials Based Electrochemical Cytosensor Based On COMSOL

The somatic cells count in fresh milk is one of the most important indicators to measure the quality of milk,which is very important to achieve rapid and accurate detection.There are many ways of cell detection and compared with the traditional electrode detection,the interdigitated electrode possesses the advantages of impedance reduction,fast steady-state signal establishment and high signal-to-noise ratio.The main research content contains the following aspects:(1)The COMSOL Multiphysics finite element simulation software is used to simulate and model for the different sizes of interdigitated array microelectrode electrochemical cytosensor,effects of different size electrodes on cell sample sensitivity are compared according to the simulation results.(2)Interdigitated array microelectrodes are prepared by photolithography and stripping process,and the electrode sizes are 30 ?m,50 ?m and 70 ?m,respectively.A three-electrode electrochemical deposition method is used to fabricate a layer of Zn O thin films on the surface of these three electrodes.The cyclic voltammetry and scanning electron microscopy show that the deposited films are closely arranged and grow well.(3)Three types of cytosensors are tested using milk samples with different cell concentrations,and the detection sensitivity of cell sensors with 70 ?m deposited nano-Zn O is best.Samples of different concentration can be completely distinguished,and the impedance can be obviously changed.Equivalent circuit fitting is performed on the detection data of 70 ?m cell sensor,and the equivalent circuit model is established.The relationship between CPEC,CPED and cell concentration in the circuit model is analyzed.Samples of different concentration can be correctly distinguished when the cell concentration in samples is more than 400,000/m L,reaching to the test standard of 400,000/m L is stipulated in China judges the quality of the fresh milk.