The Research Methods Of DNA Gold-nano Biosensors

In the later1960, biological enzymes combined with a variety of electrochemical sensors that constituted a new type of analysis equipment. After that, as an important detected part, the biosensor has been developed into an integral part of today's biotechnology. With the rapid progress of science and technology, such as fiberoptic technology, piezoelectric quartz crystal Zhen frequency technology, surface plasmon nano-technology, DNA chain replacement technique and fluorescence technique have been perfect integrated into biosensors. In recent years, these techniques especially fluorescent DNA and nano-technology hav become an important technology of the DNA biosensor.In1959, Richard Feynman suggested that the ideological model which the objects were built by individual atoms and moleculers. Nanotechnology means that the researchers would be able to operate the objects which size are between0.1to100nm. In the21st century, nano-technology especially gold nano-parties technology has become the focus of many other disciplines'research, such as physics, chemistry, biology and materials science, and has formed an important chain. Nano-technology. including the surface effect, small size effect, quantum effect and macroscopic quantum tunneling effect will continue to be one of the most science and technology in the next few years.Strand displacement technique uses adhesive between the single-stranded molecules by joining the input chain to release another strand of DNA. This technique has a variety of advantages such as sensitivity, spontaneous and high accuracy. In recent years, a lot of studies use the technology and have a good performance. Based on the specificity and predictability of Watson-Crick base pair, the DNA molecules on the nanometer scale have become a powerful and versatile engineering material. Use strand displacement to control the self-assembly of DNA nanostructures. and hybridization by the program of the complementary strand can conduct the rapid growth and diversification DNA nano-structures and nano-devices.Fluorescence refers to a certain the material triggered by a certain incident light of certain wavelength in room temperature, its atomic electrons are excited to a higher energy level emission. As soon as the incident light stops, the luminous phenomenon will disappear immediately. The outgoing light of this nature is called fluorescence. Since the advent of the fluorescence techniques, especially the fluorescent DNA technology has been taken seriously. In recent years, this technology has played an indelible contribution to the DNA nano-device, the self-assemble of DNA molecules, DNA computing and other emerging technologies.DNA magnetic particles absorption technology is based on the chain streptavidin conjugated magnetic beads as solid phase matrix, a variety of biotinylated complex such as proteins, antibodies, small molecules, carbohydrates and DNA bind to it. By using the magnetic adsorption rack to efficiently collect the beads, thus it will become the tool of corresponding experimental operating target moleculars.The innovation of this article is the integration of DNA strand displacement technology and DNA fluorescence technology and DNA magnetic particles adsorption techniques by gold nanoparticles. They are designed to be a DNA biosensor.At first, the designed DNA strand of this experiment is assumed to be a specific disease-causing genes or viral genes, and then the fluorescent DNA chain attached to gold nanoparticles by hybridization and the replacement chain is joined, we determined whether the fluorescent strand is replaced by detecting the fluorescence changes, thereby proved whether the detected solution containing the replacement chain of causative genes or viral genes which we assumed.Similarly, we also used the M-280magnetic particles to achieve the capture and release of gold nanoparticles. We observed the capture and release of the gold nanoparticles by magnetic particles through DNA strand replacement technique and determined whether the detected solution containing the causative gene or viral genes which we assumed. At the same time, both of the two approaches above were fused into the same sensor. It can be detected by two different species DNA replacement chains simultaneously which are assumed as the causative genes or viral genes through the detection of the fluorescence change and the observation of the capture and release of magnetic particle. The above experiments are successful, the addition of replacement chain into the single fluorescent modified sensor for40minutes, the fluorescence increase into1444.78%of the substrate. We will be able to observe color and morphological changes of solution by the naked eye in a single magnetic particle adsorption sensor. By adding replacement chain to make the relase of magnetic particle adsorption into the magnetic particle adsorption and fluorescence modified biosensor which the single fluorescent modified sensor. We will be able to observe color and morphological changes of solution by the naked eye.and after40minutes, the fluorescence increase into348.89%of the substrate.In conclusion, biosensors are very fast, accurate, stable and non-polluting methods and tools which providing a new method of detection for the area of molecular biology and medicine.