Study Of Modified Electrodes Based On Nanomaterials And Application In Electroanalytical Chemistry

Nowadays, nano science and technology has attracted much attention for two reasons. First, it offers the opportunity to understand the world at a deeper level. Researches in nano science and technology need new knowledge, and therefore it is time to set up new methods, new principles and even new theories. At this point, we can say that nano science and technology gives fundamental researches a wonderful perspective. Second, nano science and technology can make a great impact on our economy and society. In recent work, it has been discovered that the tiny objects (0.1~100 nm) can have electrical, magnetic, optical, chemical properties completely different from those of the same materials in bulk form. These discoveries will lead to powerful devices with new capabilities and also new materials that will impact all sectors of technology. Nano science and technology are now changing our lives. As a result, governments in most countries response to the scientific and societal challenges posed by nano science and technology, and implement many effective plans to galvanize its development.On the other hand, analytical chemistry has great importance in many research fields. As we know, with the fast development in life science, traditional analytical methods cannot meet the needs to in situ and in vivo acquire the information any more. It requires more and more new methods to understand life processes. Combined with nanotechnology, analytical chemistry can provide many new methods for the researches in life science. In other words, bioanalytical chemistry based on nanotechnology will create a new world for traditional analytical chemistry. Electroanalytical chemistry is one of the most important fields in analytical chemistry. Today, many wonderful nanomaterials have been applied in electroanalytcial chemistry and some important progresses along these lines have recently achieved. Of course, this is a new area worthy of attention and it also helps to set up new methods, new techniques and new theories.My dissertation research focuses on developing modified electrodes based on nanomaterials,which is one of most active areas in electroanalytical chemistry. All of modified electrodes we developed exhibit wonderful properties different from those based on the same materials in bulk form. In addition, this dissertation research also tries to apply these novel modified electrodes towards chromatography coupled with electrochemical detection for biological and pharmaceutical molecules, which are promising for the researches in life science. During the three years, we are adhering to an organic combination of electroanalytical chemisty, nanotechnology and life science. The details are given as follows:Part I: Study and Application of Functionalized Carbon Nanotubes Modified Electrodes(i) In Vivo Monitoring of Biological and Pharmaceutical Molecules by Liquid Chromatography Coupled with a Modified electrode based on Multi-Wall Carbon Nanotubes Functionalized with Carboxylic Acid GroupsSince the discovery of carbon nanotubes in 1991, they have attracted much attention because of remarkable nanostructures combining high surface area, high electrical conductivity, good chemical stability and significant mechanical strength. Depending on their atomic structure, the subtle electronic properties suggest that carbon nanotubes have the ability to promote electron-transfer reactions when used as an electrode in chemical reactions. However, the purified carbon nanotubes flocculate rapidly in aqueous or common organic solution, hindering their further manipulation and application. Important progress along these lines was recently achieved. In this previous work, a stable colloidal suspension in water could be made for the single-wall carbon nanotubes fuctionalized with carboxylic acid group with the assistance of anionic surfactant. In this part, much cheaper multi-wall carbon nanotubes were functionalized with carboxylic acid group (MWNT-COOH). It was found that MWNT-COOHs in common solvents did not flocculate so rapidly as MW...