| Piezoelectric bio energy-dissipationseneing technique, which incorporates energy dissipation measure technique ,is sensitive to multiple signals such as the surface loading , and the density, viscosity, conductivity, and dielectric effect of the test solution. It may present some outstanding advantages including desirable simplicity, high sensitivity, rapid response, wide detection range, effective cost, real-time digital output, and free from tracer labeling and sample purification etc. This kind technique shows an attractive future of potential applications in the biochemical diagnosis.In this paper, it was reported that theoretical analysis of dissipative effects in quartz crystal resonator; piezoelectric biosensor dissipation analyzer(PBSD) was constructed; several common liquid system was adopted as test models to reflect the piezoelectric energy dissipation real-time response characteristics; based on the immunoagglutination theory and the dissipative effects, a novel pize-immunosensing system for protein detection has been proposed; by acquiring and analyzing the response information from cells, the technology of application in cell detection strategies was explored. The present thesis is composed of the following five parts:①the important source of energy dissipation ---- friction effect, it is consist of internal friction and interfacial friction . Combining the theory of acoustic impedence responses,by analyzing and calculating, the function of slippage acoustic impedence was concluded . base on multilayer model of liquid and the models of viscoelasticity to build energy dissipation response equations.②Based on transient dissipation technique the PBSD was builded successfully in the real-time monitoring of energy dissipation at the first time. With PLC,OSC and Matlab Microsoft to control wave collecting and calculate dissipation factor. It was shown that Steady PBSD system has been established. The system has stability of≤0.32±0.13 Hz·min-1,≤0.13±0.02×10-7·min-1 in gas phase and≤0.26±0.04Hz·min-1,≤1.59±0.11×10-7min-1in water ;≤0.29±0.09 Hz·min-1 ,≤5.21±0.14×10-7·min-1 in DMEM.③The dissipation response parameter such as the density, viscosity, conductivity, and dielectric were researched. It was demonstrated that the frequency shift and dissipation factor shift is linear with ( )ρη1/2 in the range of low concentration; dielectric only affect dissipation factor change, conductivity proportion ?f and ?D .④A piezoelectric immunoassay based on nanoprobe immunoagglutination has been proposed for rapid and sensitive detection of IgG. The nanoprobes were prepared by labeling gold nanoparticles with anti-IgG antibody. And PBSD was used to monitor the changes in solution density and viscosity caused by the immunoagglutination of IgG and anti-IgG nanoprobes. Effects of pH and ionic strength were investigated. It was found that the developed immunoagglutination assay is sensitive to IgG as low as 0.19 nmol/L ,with unnecessary for immobilization of immuno- active entities.⑤PBSD sensor for detecting viscoelastic properties of hepatoma cell is researched. Using this new sensor , cell-substrate interactions and the paclitaxel impacts of HepG2 hepatoma cell viscoelasticity were monitored in real-time. The results indicate, this new piezoelectric bisensorcan detect viscoelastic properties of hepatoma cell, and it has advantages, such as real-time, undamaged, dynamic and continuous. It could be believed that the application of PBSD would be becoming more abroad and more frequently in fields such as medical treatment, sanitation, environment measurement, food safety and so on. |
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