| In recent years,with the aging of the population deepening and people's increasing attention to physical health and medical hygiene.Point-of-care-testing(POCT)technology has developed rapidly.Microfluidic technology has been widely used in POCT technology due to its characteristics of fast detection speed,small sample demand and easy integration.Lab-on-a-disc only needs a motor to drive the chip to complete the liquid delivery,and no external drive is required.Compared with the traditional microfluidic detection system,the centrifugal microfluidic system has its own characteristics,low manufacturing cost,miniaturization and automation.The centrifugal microfluidic system has great significance in nucleic acid detection,environmental detection,clinical analysis,instant diagnosis and food safety.In recent years,with the rapid development of centrifugal microfluidic technology,many mature centrifugal microfluidic platforms have achieved great success in the market.Based on such background requirements,this paper built a set of self-designed centrifugal microfluidic optical detection platform,and designed a dish-type microfluidic chip for the detection of urine retinol binding protein.The centrifugal microfluidic system for biochemical detection built in this paper included a centrifugal device driven by a 42 stepper motor;a dual optical path compensation device for absorbance detection composed of photodiodes and amplifying modules;an isothermally controlled temperature device and a visualization device for observing the liquid flow in the chip in real time.Among them,in addition to the visualization device using the camera's own software for control,all control systems were controlled by python and single-chip microcomputer,and the entire experimental process was automated,and all data was collected to the upper computer by the acquisition card to save.In response to the need of urine for the automated and the rapid detection,microfluidic technology and biochemical analysis technology were adopted to design and fabricate a disc microfluidic chip used for urine biochemical detection.The chip consisted of microfluidic channels,capillary valve,siphon valve and ferrowax valve realizes the sequential transportation of the sample and reagent,mixing and detection.And COMSOL software was used to model the structure of capillary valve and siphon valve and optimize the rotary frequency.Next a fully automatic urine biochemical detection system was generated based on a disc microfluidic chip.The effects of light source fluctuations and background interference on test results were reduced by dual optical path and dual wavelength detection.The detection system was characterized by urinary retinol binding protein(RBP).The results demonstrate that the CV of the system was 1.3%-2.46%,and it indicated that the system had good repeatability.The calibration curve showed the linear correlation between urinary RBP concentration and the absorbance(R~2=0.995).The four identical unit on the chip could perform a multi-sample or multi-parameter detection in parallel,in which it had a potential to be applied for the rapid of urinary protein detection.On the basis of the above work,it is hoped that a POCT instrument will be built in the future on the basis of the off-center microfluidic platform,so as to truly realize the full automation of sample in and result out detection and make a contribution to biomedical detection. |
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