The Application Of Novel Type Interdigtal Electrods Piezoelectric Sensor In Biological Analysis

Organism, microorganism, cell or biological substance is performed as the sensitive elements in biosensor to sense physical or chemical stimulation outside the world. And the response of various organism parameters or physical and chemical parameters were caused by the stimulation. At the same time, the biosensor receives and senses these responses and makes evaluation. Biosensor and its measurement technique can be not only applied to detection the microorganism, metabolism as well as biology study, but also provide scientific and effective method for pharmacology and toxicologic study. Therefore, biosensor has been widely used in clinical diagnosis, function and toxicity analysis of drug, environmental toxicant monitoring, food safety analysis and biologics quality control and other relevant fields.On the series piezoelectric biosensor research, we have spent many years on it and have achieved some progress as well as some accumulation. First, the development status and development direction of piezoelectric biosensor were introduced in this thesis. It is well known that piezoelectric sensor includes mass sensitive direction and non-mass direction. The non-mass direction is the series piezoelectric quartz crystal sensor. Then, the detailed research of series piezoelectric sensor in our laboratory was introduced and some achievement was also inrodeuced. Next, a sensitive piezoelectric biosensor was structured by combineding with microelectrode and piezoelec-tric crystal in series after extensive research on series piezoelectric quartz crystal sensor.Design microelectrode, simulating calculation its electric field and optimization research work plays vital role in this thesis. Especially, the physical and chemical parameters of the microelectrode were detected and the constructed biosensor based on microelectrode and piezoelectric crystal was used to detect the protain, cellula and bacteria. Experimental research was also performed using the microelectrode.Firstly, several parallel interdigital electrode with different dimensions were designed and carried out to simulat calculation using software of multi-physics field. The result was compard and make a comparison of electric field distribution between interdigital electrode and counter electrode, simulation result shows that the electric field distribution of alternative embedded structure of interdigital electrode has more stronger electric field intensity and more intensive electric field distribution compared with traditional parallel plate against electrode, therefore, interdigital electrode has higher mass transfer efficiency against its test target.Then, in order to make an experimental research on interdigital electrode series piezoelectric biosensor which was structured using interdigital electrode in actual biological sample, the experiments for detection protein sample were carried out and the result showed that the IDE piezoelectric biosensor has higher sensitivity compared with piezoelectric biosensor structured by counter electrode. In addition, through conducting modification on interdigital electrode so as to structure an analysis of bioprotein which choosing lysozyme as analysis target. The experimental result also shows that it has achieved success in recognition and analysis of biomolecule with high selectivity and high sensitivity. Because the interdigital electrode is a kind of symmetrical electrode with horizontal distribution, which can conduct surface modification treatment well, so that it has more unique advantage and convenience in special function reconstruction.Finally, based on the result analysis of simulation study of interdigital electrode, the ring electrode has been put forward in this paper, designed and processed various ring electrodes with different dimensions. The electric field of the ring electrodes have been simulated and calculated on the space over its electrode surface, the result shows that the electric field distribution of ring electrode is more reasonable compared with the parallel interdigital electrode. According to experimental detection of the simulation sample, it can be seen that to increase cylinder number will remarkably improve the sensitivity of the sensor. On the basis of simulation result, it takes advantage of optimized electrode and piezoelectric crystal series to structure series piezoelectric cell-based sensor. Then, the equivalent circuit, piezoelectric theory model and parameter of sensor were researched. This kind of cell-based sensor used to monitor Hela cell on line. Through testing the stability of sensor, monitoring the growth of Hela cell and foreign drug study, the research results all indicate that this kind of sensor has high sensitivity and it can on line monitor cell growth and analyze drug in due time.