Directional Assembly Of Functional DNA And Its Application In Biological Analysis

With improved understanding of structure and function of human gene, andthe development to the Human Genome Project, DNA separation and analysis hastaken an increasing important role in the areas of clinical, diagnosis, medicine,epidemic prevention, environmental protection and bioengineering. Since1953,Watson and Crick discovered the DNA double helix structure of DNA, which wasdeveloped gradually. Now people have been using the DNA to constructcomplicated variety of graphics. How to make use of directional assembly of DNA,showing its excellent physical and chemical properties in electrochemical sensors,has been the focus of research in the field.This paper studies on the functional nucleic acid assembled electrochemicalDNA sensor and its applications in research, the main contents are as follows:The First Chapter, a brief introduction, presents the concept and classificationelectrochemical DNA biosensor, the main ways of signal amplification&theapplication of functional nanomaterials in the biosensor. Finally, we provide thehypothesis of this thesis.Chapter II, the sandwich structure of DNA-based ultra-portable multi-signalcharacteristics, based on a protective effect of folic acid folate receptor DNAconnection. Meanwhile, we examine the effects of different experimentalconditions, under optimal conditions electrochemical detection of folate receptoramplification with high selectivity. And the sample detection error is smaller.Chapter III, We designed supersandwich structure G-quadruplex DNA aselectrochemical sensors. Owing to the fact that cisplatin has a strong combinationwith the guanine, this electrochemical sensor successfully applied to the detectionof cisplatin. Under the optimized the conditions, you use differential pulsevoltammetry and resistance to detect cisplatin, and the experimental results aresatisfactory.Chapter IV, We design specific DNA sequences to form G-quadruplex-supersandwich structure as platform. Due to the fact that thrombin can hinderelectron transfer, the amplification detection of thrombin is achieved. The sensorhas a high selectivity and a good linearity range.Chapter V, We layout a Dual-hairpin DNA structure as electrochemical sensortemplate, in which the label molecules near on the surface of electrode promotingthe electron transfer. The electrochemical sensor is applied to detect DNA,thrombin and adenosine triphosphate successfully. Meanwhile, the sensor has highselectivity, stability and regeneration performance.Chapter VI, we successfully prepared titanium tube nanomaterials, which isalso characterizaed. Utilizing the adsorption of titanium tube, phosphorylated DNA and the amplification of gold nanoparticals, we detect polynucleotide kinasesuccessfully. Finally, we also testify the effect of different salt solutions to thesystem; which is consistent with our idea.