Construction Of DNA Biological Fluorescent Probes Based On Nanomaterials And Their Applications In Cell Imaging

With the deterioration of the environment, the chance of human cancer is increasing. Development of highly sensitive detection of tumor cells in medicine is an important means of early diagnosis and treatment of cancer, with the very early diagnosis in the field of cancer clinical, efficiency and low toxicity targeted anti-cancer drug is recognized the best solution of cancer cure. The article complex DNA sensors, nanotechnology, imaging technology designed probe that can specifically recognize the Ramos cell, and achieved good results in terms of sensitivity and specificity The contents of the thesis are as follows:1. We designed a new method based on rolling circle amplification technology and double-color fluorescence signal for the visual detection of target DNA.In this experiments we use green and orange quantum dots mark the rolling circle reaction product. In the presence of substrate rolling circle reaction can always go, so it will produce a very long strands of DNA, then connected quantum dots which can achieve signal amplification and visual detection of target DNA.The green quantum dot as a reference point of the experiment in this system,orange quantum dot as a product of the detection of the target DNA. The method of this double-color signal method of detecting target DNA, to avoid the trouble of using only one quantum dot caused by a single signal is difficult to distinguish the interference signal. Double-color signal method can achieve the visual detection of the target DNA, and also provides the basis for the visual detection of single molecules of DNA, need to be more in-depth study.2. We have synthesize a composite nanoparticles fluorescent probe,which binding aptamer DNA and CdTe quantum dots and mesoporous silica nanoparticles as the carrier. The method has been successfully used for fluorescence imaging detection of Ramos cells. After the amino function of the mesoporous silica can be combined with a large number of fluorescent quantum dots and aptamer DNA chains, so it has a high fluorescence intensity as well as the specific recognition. Change the DNA sequence of the aptamer recognition sequences for other biological unit, we can achieve some other detection purposes. As the mesoporous silica has pore structure and good biocompatibility, it also can be used as a drug carrier. The experiment provides the basis for the early diagnosis and treatment of tumor cells.3. We carried out a research based on the self-assembly of CdTe quantum dots@AnnexinV-DNA nanowires fluorescent probe. The probe is designed a sequence that can specifically binding with the target tumor cells in order to achieve specific detection. The more important is the use of the structural characteristics of the probe, to achieve the physiological changes of tumor cells by the drug directions. The probe not only achieve specific detection of tumor cells, but also can indicate normal, apoptosis, necrosis, three cell physiological state. After further refine and structure optimization, the probe can produce some inspiration for the development of the new multi-functional biological imaging probes.