The Study Of Improve The S/N Of Capillary Electrophoresis Fluorescence Signal

The detection technology of biochip is one of the most important parts of biology and chemistry analyzes system. In the analysis systems of microfluidic biochips, laser-induced fluorescence (LIF) detection is one of the main means of Capillary Electrophoresis (CE) chip detection, because of its high sensitive. This paper is to enhance the design efficiency and performance quality of the circuit and improve the signal-to-noise ratio of the output fluorescent signal of confocal laser-induced fluorescence detection system which has been designed. From the two part of optimize design of the fluorescence signal detection circuit and enhancing signal-to-noise ratio mathematical approach, this paper study on improve the sensitive and the signal-to-noise ratio of the confocal laser-induced fluorescence detection system.Base on the analysis of the capillary electrophoresis chip fluorescence signal detection system and its electrophorgram characteristics, this paper discuss the noise source of the fluorescence signal detection circuit. Then for reduce the noise of the system, this paper optimize the design of the fluorescence signal detection circuit. Using the technology of low-noise amplifier and filter, this paper completed the optimize design of the capillary electrophoresis chip signal acquisition hardware circuitry and the relevant software. Through the performing circuit simulation, circuit analysis and circuit parameter analysis functional of OrCAD, this paper design of the amplifier circuits of the fluorescence signal acquisition system and choose more reasonable parameters of the circuit. And the signal-to-noise ratio of capillary electrophoresis fluorescence signal has been improved.This paper use the Hadamard transform capillary electrophoresis system for enhancing the signal-to-noise ratio (S/N), and demonstrated its performance using a simple electrokinetically gated injection approach and the digital signal processing technology. A Hadamard transform fluorescence signal acquiring and processing system was designed using MATLAB software. This system includes GUI user interface and could achieve the functions as follows: importing the fluorescence signal data from the text files or the Visual C++ software; exporting the data after the HT and saving them as a text file or bmp file; calculating the result of HT; generating the pseudorandom binary sequence (PRBS) and painting the fluorescence electropherogram before and after the HT. The result of the testing show that the Hadamard transform capillary electrophoresis system this system can achieve the acquiring and processing of the fluorescence signal.