Research And Implementation Of Microfluidic Device For Rapid Nucleic Acid Detection

In human society,various infectious diseases have been continuously threatening human life and health.For example,the global outbreak of COVID-19 in 2019 has had a very serious negative impact on global public health,social stability,and economic development.Polymerase Chain Reaction(PCR)is one of the gold standards for infectious disease detection.However,the precise thermal cycle control and complex instrument systems limit the application of PCR in Point-of-Care Testing(POCT)in the field.Thus,researching simple,efficient,convenient,and low-cost nucleic acid amplification detection methods and devices is of great significance for rapid on-site detection of POCT.Due to its advantages in fluid automation and reaction integration,microfluidic technology provides a reasonable solution with its own characteristics for achieving fast and integrated nucleic acid detection.This article focuses on two aspects of microfluidic devices for rapid nucleic acid detection.Based on the principle of convective PCR amplification,a high-throughput and real-time nucleic acid amplification detection method and device that can achieve on-demand detection were studied.This device utilizes constant temperature heating of the upper and lower layers of the reaction tube to construct a stable thermal circulation inside the reaction tube to implement the thermal cycling process required for PCR reaction.Within 30 minutes,it achieves simple and fast real-time nucleic acid amplification detection.Based on the integrated design of photo electromechanical integration and software algorithm analysis,on the one hand,it allows for high-throughput sample detection.On the other hand,it allows for the real-time addition of new reaction tubes without interfering with the current well site amplification detection,achieving efficient on-demand detection.Research has achieved a highly integrated fluorescence detection module,achieving highly sensitive fluorescence detection.In order to overcome the effect of the long operation time of the system,the internal heat aggregation,and the working stability of the system,the optimized design of the system was carried out to ensure the ideal detection performance.Based on microfluidic technology,an integrated,automated,and portable centrifugal microfluidic amplification detection system was studied by combining RPA isothermal amplification with colloidal gold strip detection.The microfluidic system includes a centrifugal microfluidic chip and a supporting driving device.Through the mutual cooperation of the two,it can complete isothermal amplification reactions,reaction reagent transfer,mixed dilution of amplification products,and detection of amplification products based on colloidal gold strips in a fully enclosed environment.Within 25 minutes,an integrated detection process was achieved,effectively overcoming aerosol pollution.On the one hand,with the fluid drive of centrifugal microfluidic chips,the entire detection process can be automated.On the other hand,with the flexible mixing function of centrifugal microfluidics,it is possible to efficiently mix and dilute high viscosity amplification product reagents,ensuring the detection performance of colloidal gold strips.With the visual detection method of colloidal gold strips,the detection process can be conveniently completed without the need for additional detection devices.