Research On ToRSV-oriented Biosafety Detection Technology Based On Microfluidic Impedance Method

Faced with the frequent occurrence of biosafety problems caused by animal and plant pathogens and the significant demand for fast and accurate detection technology in the field of biosafety detection,this study designed the microfluidic chip microchannel and micro-interdigital electrode numerical simulation to a microfluidic chip with embedded interdigitated array gold microelectrode,and a microfluidic impedance detection and analysis system for rapid and accurate detection of viruses.Using this system,the impedance detection of tomato ring spot virus was achieved,and a quantitative detection model between different concentrations of virus and impedance values was obtained.The biosafety detection technology based on the microfluidic impedance method provides new ideas for the quantitative detection of viruses in the field of entry-exit inspection and quarantine and biosafety detection.The main research contents and results are as follows:（1）The principle of microfluidic impedance detection and the method of electrochemical impedance spectroscopy were researched.A microfluidic chip with embedded micro-interdigital electrode was designed and manufactured.At the same time,a microfluidic impedance detection and analysis module with a drive module,a detection module and an analysis module was built.The analysis system establishes a quantitative virus detection mode on the microfluidic chip:the optimal measurement frequency is selected based on the change in impedance difference,and a quantitative model between different concentrations of viruses and impedance values is obtained at the optimal frequency.（2）Comsol Multiphysics was used to perform microchannel flow simulation,micro-interdigital electrode field strength distribution simulation,and impedance response simulation of electrodes with different parameter shapes.The microchannel simulation results show that the gold interdigitated electrode should be set at 10mm from the entrance of the microchannel.The micro-interdigitated electric field strength simulationresults show that a micro-interdigitated electrode with an electrode width of15μm,an electrode spacing of 15μm,and an electrode height of 100 nm was selected as the detection electrode used in the experiment.（3）In the detection frequency range of 100K-1Hz,the impedance detection of tomato ring spot virus with a concentration range of 10～10^-3μg/m L was performed,and the detection time was 30 minutes.Under the optimal detection frequency of 10.7Hz,the quantitative relationship between the tomato ring spot virus concentration C and the impedance value Z was established,and the detection limit was 3.4 ng/m L.Compared with conventional detection methods,the measurement results have the advantages of lower detection limit and shorter detection time.In addition,the microfluidic impedance quantitative detection of tomato ring spot virus has good specificity.