Miniaturization Technology Research Of Optofluidic Glucose Measurement System

The continuous glucose monitoring technology based on transdermal extraction of interstitial fluid(ISF)is a hot research topic,due to its advantages of minimally invasive,real time and high precision.In order to further improve the measurement precision and promote the development of continuous glucose monitoring technology,this paper studied the key technologies of miniaturization,portability and automation of the original system with a large volume and complicated operation processes.And an optofluidic system was built for minimally invasive continuous glucose monitoring.The main work in this paper is as follows:(1)The miniaturization design and fabrication of each module in the optofluidic system.After discussing the problems of the original system,the structure of the ISF transdermal extraction chip was optimized,the micro sample cell for enzyme colorimetric detection was designed according to the volume of the mixing sample,and the micro quantitative mixer consisted of a quantitative injection module and a micromixing module was designed.Then the extraction chip and the quantitative mixing chip with five layers and four layers of PDMS respectively were fabricated using micromolding method.And the micro sample cell was fabricated with glass using UV curing method.(2)The test and evaluation of the functional components of the optofluidic system.First,the performance of the improved ISF transdermal extraction chip was tested by physiological saline.Then,the quantitative module was tested based on the optimal structure selection of the micro quantitative mixer and the test of the micro sample cell in the glucose concentration range of 0-10mg/dL(R~2=0.9986).And the testing results of the quantitative module show that it can maintain good stability for a long time with the average absolute error below 4.7%and has high linearity with a squared correlation coefficient of 0.999.(3)The design and evaluation of the miniaturization optofluidic system.The miniaturization optofluidic system was established by connecting the micro quantitative mixer,the micro sample cell and the improved ISF transdermal extraction chip together.To test the miniaturization optofluidic system,experiments were carried out by using the glucose solution to simulate the ISF.The results show that the average absolute error of the system for the measurement of the sample solution with different glucose concentrations(30-200mg/dL)and same volume(0.5?L)is only2.04%;and the average absolute error for the measurement of the sample solution with different volumes(0.5-2.5?L)and low glucose concentration(30mg/dL)is only1.27%.These results verified the feasibility of the miniaturization optofluidic system for high precision monitoring of glucose samples with microvolume and low concentration.