Zinc Oxide And Related Novel Nano-biomaterials Applied For Preparation Of Biosensors Based On Enzyme And Immunochemistry

Recently, there has been rapid development in the research and application of biosensor, which can detect analytes selectively using the specific reaction of bioactive materials such as the enzyme-substrate, enzyme-coenzyme, antigen-antibody, incretion-acceptor and so on. Biosensors could be applied directly in the determination of complex samples using the specific bio-recognition of bioactive materials. Meanwhile, biosensors can be applied to a wide rage of analytical tasks, including clinical diagnosis, control of industrial process, environmental monitoring, evaluation of the safety of chemicals, analyses in food and pharmacy industries because of its high sensitivity, good selectivity, no sample pretreatment and integrating the processes of the sample separating and detecting.In the design and fabrication of biosensor, the development of a simple and effective strategy for the construction of sensitive membrane on the electrode is a crucial step. Nano-crystalline particles, exhibiting a large surface area with diameter less than 100 nm, high surface-activity, good biocompatibility, strong adsorption and great efficiency of catalysis, might be favorable for constructing biosensor. One-dimensional materials such as nanorods and nanowires have attracted much attention due to their specific physical properties and interesting application in nano-devices. The study of one-dimensional (1D) materials has become a potential frontier in nanoscience and nanotechnology in the last few years. This thesis focuses on developing new nano-biomaterials and their immobilization strategies in biosensor-fabricating for the purpose of improving the performance and long-term stability of biosensors. Therefore, nano-sized flower-like ZnO (Chapter 2) and ZnO nano-rods (Chapter 3,4) were synthesized by a simple hydrothermal method and a solvothermal route, respectively. The two methods are convenient, environment friendly, inexpensive and efficient process. The phenol,H₂O₂ and glucose biosensors based on the ZnO obtained by these two methods showed excellent performance. In addition, an immunosensor based on the horseradish peroxidase and antibodies functionalized liposome was constructed. The details are summarized as follows:(1) Nano-materials have good biocompatibility. They can keep the activity of biomolecules due to the desirable microenvironment, and enhance the direct electron transfer between the enzyme's active sites and the electrode. In chapter 2, a novel phenol biosensor was proposed by immobilizing tyrosinase to nano-ZnO particles. The...