Serum Immunoassay And Urine Detection Based On Microfluidic Paper-Based Chip

With the development of technology,people’s standards of living have improved,and their awareness of physical examination has gradually increased,people pay more attention to their own physical examinations in recent years.However,at present,disease diagnosis,biochemical analysis and environmental testing still rely on expensive and cumbersome experimental equipment,which is difficult to achieve in economically underdeveloped areas.Otherwise,large-scale instruments are required professionals to operate,which cannot to meet people’s needs for portable home testing.In recent years,Microfluidic Paper-based Analytical Device(μPAD),an emerging analytical platform,is attracting more and more attention of analyst.Compared with traditional polydimethylsiloxane,glass and other materials,μPAD is simple to operate,portable,non-toxic degradation and good biocompatibility.And it can be combined with a variety of detection methods to form different sensors,which decreases the dependence on instruments and equipment.It shows certain development potential and application prospects in the analytical methods of medicine,environment,and food.Among the paper chip sensors constructed by different detection methods,the colorimetric method is one of the most popular methods.It has the characteristics of simple qualitative analysis that can be observed by eyes.Colorimetric sensors can be combined with a smartphone or a camera to obtain color images,and software can be used to measure the color intensity for quantitative analysis.In this thesis,based on the colorimetric μPAD,a bilayer spinning microfluidic paper chip device was developed and constructed.The device uses a rotary valve to control the incubation process and washing/adding process of the chip device,miniaturizes the experimental platform and facilitates the possibility of developing μPAD instant assays.This thesis mainly includes the following two parts:1.Determination of inflammatory factor markers C-reactive protein and serum amyloid A.A portable and inexpensive centrifugation device for electric yo-yo was first developed,and serum was obtained by centrifugation from whole blood using centrifuge.And built a portable double-layer rotating paper chip device,each layer of chips was a pattern,in order to reduce the stacking of the number of chip layers.The double-layer paper chip rotating with the rivet as the axis makes the detection plate and the washing plate relatively independent,and can complete the multi-step incubation and multi-step washing process of ELISA.We close the inflammatory factor C-reactive protein and serum amyloid A as the detection substances.Combined with a smartphone and Image J,the two targets were determined successfully.The feasibility of the chip device was then verified by testing the actual samples in the hospital.This approach of combining a portable mini-centrifuge with a paper-on-a-chip device could provide a new platform for low-cost and rapid detection of inflammatory biomarkers in resource-limited settings.2.Detection of multiple targets in urine.Based on the fact that urine contains specific and highly sensitive biomarkers for the diagnosis of disease,we test for multicomponent targets in urine.A double-layer paper chip device controlled by a rotary valve was designed and constructed.The fluid can flow from the auxiliary disk to the detection area in the detection disk through the drive of its own capillary force.The multiple detection areas of the device were evenly distributed to ensure that the distance from the sample cell to each detection area was equal.The simultaneous detection of several targets such as glucose,albumin,nitrite,p H,and hemoglobin in urine can be accomplished by colorimetric method.The effectiveness of the device was verified by detecting samples of volunteers by standard addition method.Based on the characteristics of rapid analysis of the device,the paper chip analysis device controlled by the rotary valve has potential application value in medical diagnosis.