Research On Key Technology Of Preparing And Quantitative Detecting The Immunofluorescence Chromatography Test Strip

Immunochromatographic technique has been widely used in clinical diagnosis, food and drug control, environment monitoring and other field with shorter duration, easier operation, and lower cost. At present, immunochromatographic technique is developing toward the characteristics of quantitative and high sensitivity. While ordinary colloidal gold labelled strip, which is not sensitive enough, can only obtain a qualitative result. Therefore it can no longer match the demand while conducting ultra-trace detection, pesticide residue detection, and industrial standards formulation. Fluorescence immunochromatographic technique can improve detection sensitivity and help create condition for quantitative detection, while retaining the main advantage of immunochromatographic technique like speediness, specificity and simpleness.A high throughout detector aimed at maintaining fluorescence immunochromatographic strips was herein designed. The detector was set up based on confocal induced fluorescence detection structure and step-motor driven two-dimension scanning structure. The detector adopted LED as excitation light source, photodiode as electro-optic sensors. And self-designed dichroic cage cube was engaged to set up a confocal optical structure with lower cost and smaller volume. Lead screw, pinion and rack driven by step-motors were used to help set up the electrical and mechanical structure of the detector, thus the IFD system can maintain multi-channel strip with its photodiode. A FPGA chip was used as MCU to control the electrical and mechanical structure, modulate the LED light source and acquire signal with high speed ADC. Digital phase sensitive detection algorithm was implemented on FPGA to restrain the noise. On this basis, the key technology of preparing strips labeled by quantum dots was studied.Strips used to maintain the concentration of NT-pro BNP were bought from the market to test the performance of the detector. The response of the detector and the concentration of NT-proBNP were found linear in a concentration range of 9.375~600 ?, and the equation was: = 0.0025 + 0.9225( = 0.9493) in which y and x respectively represented the fluorescence intensity(V) and the concentration(pg/m L) of NT-proBNP. It took 2 minutes to quantitative measure the fluorescence intensity of a cluster made of eight different ICTS bought from the market, indicating that the detector had the ability to realize quantitative detection of ICTS with high throughout. On this basis, key issues like the conjugation of quantum dots and biomolecule, the purification and biological activity of the conjugation, the selection of materials and the assembly processes of ICTS were studied in this paper. Some fruitful findings has been achieved and foundation for quantitative detection and further optimization has been provided.