Novel Electrochemical DNA Biosensors Based On Carbon Nanotube As A Probe Carrier

Recent intense interest in the use of rapid genetic analysis as a tool for understanding biological processes, in unlocking the underlying molecular causes of disease, and in the development of biosensors has led to a need for new sensitive and arrayable chipbased analytical tools.DNA biosensors, which are designed by combining remarkable sensitive sensor techniques with DNA specificities, have many advantages such as robustness, sensitivity and broad detection scopes. According to the different kinds of transducers, DNA biosensors have been mainly classified to electrochemical DNA biosensors, piezoelectric crystal DNA biosensors and optical DNA biosensors.Electrochemical DNA sensor is a novel biosensor. Compared with traditional radiochemical technique, it is faster, more sensitive, simpler and unpolluted, and it can not only recognize molecule but also separate and purify genes. Therefore, it is practically significant in molecule biology and biomedicine engineering.Nano-materials, with their size in the range of 1.0~ 100.0 ran, are currently under intense investigation owing to their special properties. Due to their small size, these materials exhibit quanta-size effect, small-size effect, surface effect and tunneling effect which provided a new research method for DNA detection and prompt the development of chemistry and biosensor rapidly.The aim of the present work is to develop nano-materials-based novel electrochemical DNA biosensors, using carbon-nanotubes (CNTs) loaded with Ag nanoparticles (Ag-CNTs) and microelectrode. Based on coupling with nano-materials-based amplification units, DNA hybridization, immobilization techniques and nano-technology, two kinds of electrochemical methods for the detection of special DNA sequence are developed. Compared with other methods, the new methods are simpler, rapider, and more sensitive. A part of research work in the thesis is financially supported by the National Natural Science Foundation of China (Grant No. 20375025).A review section and research section are included in the thesis. In review section, the basic principles and characteristics of electrochemical DNA biosensors and principles of DNA detections are introduced. The principles and characteristics of various kinds of DNA detections are summarized. Trends of electrochemical DNA biosensors in DNA...