Research On Detection Technonlogy Of Plasma Fibrinogen Microfluidic Chip

Fibrinogen(FIB)a macromolecular soluble glycoprotein isolated from plasma is an important coagulation factor in the body’s hemostasis.Closely related to the occurrence of various cardiovascular diseases in the human body,it is one of the important contents of medical clinical and life science research.However,the current detection methods generally have a series of problems such as high cost and slow detection speed.Therefore,how to use modern detection technology to achieve FIB concentration detection has important theoretical and practical significance.Based on the research and analysis of the development status of microfluidic technology at home and abroad and the traditional FIB detection methods and principles,this paper proposes the use of microfluidic technology to detect fibrinogen concentration.Firstly,the mechanism of absorbance detection,that is the mechanism that the linear relationship between the amount of change in absorbance and the concentration of liquid to be tested is studied theoretically,and the transmission turbidimetric method realized by photodetection technology is used as the FIB detection method.Secondly,based on the research and analysis of the microfluidic flow characteristics,the microfluidic chip structure was simulated based on the finite element method using COMSOL Multiphysics software.The optimal parameters of the chip structure were selected according to the simulation results to determine the microflow for FIB detection.The specific structure of the control chip,that is,the injection area of the angle of the 70°Y-type two-phase channel,the inner rib type micro-mixing reaction zone with a width of 200 μm,and the detection area consistent with the sensing surface of the photodetector.On the basis of completing the development and design of the dedicated microfluidic chip,the FIB detection system was built.The system consists of four parts: light source,photoelectric conversion circuit,signal conditioning circuit and software.By studying the absorption characteristics of plasma FIB,the 660 nm light-emitting diode most suitable for FIB detection is selected as the detection source of the sample to be tested.In order to avoid the interference of ambient light and stray light on the system,the modulation and demodulation circuit was developed,.which effectively overcomes the interference of the external environment to the system.As to the problem that the signal collected by photoelectric detection has large noise interference,the signal conditioning has been developed.The circuit realizes the suppression of the interference signal through the filtering process and the amplifying signal process,thereby improving the accuracy of the FIB detection result.The upper moniter uses the Lab VIEW platform to develop software for data analysis,processing,storage and real-time display.By measuring the change of absorbance in different concentrations of standard plasma coagulation process,the corresponding relationship between concentration and absorbance change was obtained,and the calibration formula was fitted.The correlation coefficient was97.71%.The plasma FIB of unknown concentration is then detected and the concentration is determined according to this formula.Finally,the performance of the detection system was verified by experiments.The dispersion coefficient was 2.07% and the accuracy was 6.08%.The microfluidic chip technology into plasma fibrinogen concentration detecting turbidimetry based,to some extent to achieve the miniaturization and the instrument microvolumelization agent,without destroying the fiber having a high precision,low sample and other advantages.The passive micro-hybrid structure embedded in the microfluidic chip saves cost and the preparation process is simple compared to the active hybrid structure chip that requires external field interference.The design of the microfluidic chip detection system enriches the clinical detection method of fibrinogen concentration,and provides a broader idea and development direction for the miniaturization and portability of blood coagulation detection.