The Application And Research Of Nanotechnology In The Chemisensor

Nano technology is based on nanodimension materials. Such functions as gas sensibility, humidity sensibility, thermal sensibility, pressure sensibility which are shown by its particular volume effect, surface effect, quanta dimension effect, and quanta tunnel effect have displayed an enormous applying prospect in lots of fields. Nanodimension materials are applied to chemisensor, which will be helpful to integrate and intelligence the gaining, transmitting and managing the information. And chemisensor will become more sensitive and reliable. Its functions will be consummated and capability improved.In this thesis the research on nanodimension materials and chemisensor since the middle and the later period of the 1980s is first introduced. Then the conjoint application of nanodimension materials and chemisensor are summarized: 1. Nanodimension materials are mainly characterized of gas sensibility, humidity sensibility, thennal sensibility, pressure sensibility, high biological activity and high electronic transmitting capability in chemisensor. Therefore, nanodimension materials can be used to made more sensitive, quickly responsive, strongly stable sensor with a long life-span. 2. The production and application of nanosensor brings the incomparable superiority compared with the normal technology. For example, its high differentiation rate, small volume and tiny specimen demand endow it with brand-new mission. So far Nano optical fiber chemisensor has been developed and applied to such fields as chemical determination, bio-medicine. 3. Nano-particle membrane is divided into thick membrane and thin membrane. The thick membrane is prepared mainly by calcinations andgas sediment. The thin membrane is prepared mainly by sputtering, spray-heat-decomposition, vacuum evaporation, chemidepositton., vapor deposition, sol-gel process and hydrolysis. Nano-particle membrane is applied to chemi-sensor, which will be helpful to determine the gas that is detected difficult and lower the working temperature.In this thesis Nano Ag2O is first modified into carbon paste electrode and a contrast on both electrochemical capability is studied. Nano Ag2O, which is synthesized by feasible chemical method, with a 40-nm-long particle diameter, is characterized of high specific surface area, high activity, intense absorbability and high catalytic efficiency. It is modified into carbon paste electrode in certain scope. And its electrochemical capabilities are experimented in conditions with different compositions and different buffer. My experiments show that Nano Ag2O can obviously improve the electrochemical capability of carbon paste electrode and so intensify the electrode's absorbability, transmit electric charge with a high capability. The modified electrode including 16% Nano Ag2O, 17% paraffin, 67% carbon powder has the best peak form, high peak current, large peak area and displays superior electrode capability in the 0.2M HNO3 buffer.Gold nano-particle is expected to be applied widely to biosensor because of its high catalytic activity and high biological compatibility. My thesis synthesizes the 10-nm-long particle diameter gold nano-particle with sol-gel process, introduces it into dextrose sensor, uses nuclear microporous membrane to produce biological active membrane for research, and then analyzes the electrode's responsive mechanism, gold nano-particle's effect to the response of electrode current, and tests the electrode's capability. Gold nano-particle, the good electric conductor, with an excellent biological compatibility, can transmit electron betweenthe redox center of the glucose oxidase. Gold nano- particle has large specific surface area, high superficial free energy, so glucose oxidase can be forcefully fixed in the surface of nano-particle and cannot leak easily from enzyme membrane. The experiments show that gold nano-particle can obviously intensify the responsive sensitivity of the electrode and so it can be used to produce the sensor with a high selection and good stability.In this thesis n...