Study Of Molecular Diagnostic Technique Based On Infrared Image Processing And Improved Chronoamperometry

Molecular diagnosis is based on the theory of molecular biology, and it studies the structural and expressional regulation of the genetic material of humans to serve for disease diagnosis, treatment, monitor and prognosis judgment. Quantitative PCR (Polymerase Chain Reaction) is an expansion in vitro technology that widely researched and employed in the field of molecular diagnosis, which can not only analyze gene mutation but also detect the amount of DNA replication. Real-time and quantitative electrochemical PCR is a novel technology that combines the electrochemical detection methods with the PCR technique. By detection of electrical parameter of the active substances in real-time in the PCR reaction, it can quickly and quantitatively analyze the DNA replication. Compared with the fluorogenic quantitative PCR method, electrochemical PCR technology has higher sensitivity, lower cost and easier operation. Electrochemical detection is usually influenced by the undulate temperature. To reduce the temperature jamming in the PCR process, this paper use infrared thermal imaging technique to measure the temperature of detection samples in non-contact model to correct the detection curves in real-time. The main contents covered in this paper are as followings:(1) Introduction of research significance and developmental status of this project; Elaboration of PCR technique and electrochemical biosensor; Statement of global design of molecular diagnostic system based on electrochemical analysis.(2) Improvement of traditional chronoamperometry (CA); Establishment of mathematical model of improved chronoamperometry and its numerical solution; Simulation of i-t curves and some parameters related to peak currents.(3) Elaboration of framework of molecular diagnostic system; Augment of circuit modules of the improved CA based on hardware for electrochemical detection designed by our group previously; Design of signal display and processing.(4) Non-contact infrared thermal imaging technique in temperature detection process constitutes by two parts:image processing module realizing filtration of pattern noise and edge detection and strengthen; Temperature conversion module realizing temperature measurement of the circular hole.(5) Using electrochemical molecular diagnostic system for experimental test; The experimental results showing the validity and feasibility of the improved chronamperometry; Real-time detection of oral cancer DNA amplification, and its experimental and theoretical analysis, as well as result correction.This paper developed a molecular diagnostic system based on electrochemical analysis. By employing infrared thermal imaging technique, real-time temperature measurements of detection reagents were realized. Moreover, according to the change regulation of temperature, the detection curves could be corrected. Therefore, stable and real-time detection operation can be easily realized using this systern, which is helpful for the popularization and application of electrochemical molecular diagnostic technology.