The Study On Application Of Aptamer In The Detection Of Protein And Pharmaceutical Analysis

Aptamers are a series of oligonucleotides (DNA or RNA) contain18to60bases, which was selected from SELEX that can target protein, metal ions and cells through the binding affinity and specificity between it and the target. Owing to the great advantages, including facile synthesis, good stability, easy modifications and so on, aptamers have been widely applied in the fields of bio-chemical analysis, environment analysis, cell imaging, etc. So, in this thesis, we investgated the application of aptamer in the analysis of proteins and medicine on the base of its special properties as follows,1. A facile chemical reduction synthesis route of unitary emitting and targetable Silver nanoclusters (Apt-AgNCs) in one step was developed and the prepared AgNCs emit intense yellow fluorescence. On the basis of the binding affinity, we present a new and lable free method for intracellular prion protein (PrPc). PrPc in the range of42.4-192nmol/L could be selectively detected with the linear equation of (F0-F)/F0=0.010+2.3×10-3c, the correlation coefficient (r) of0.9942and the limit of determination (LOD) of30nmol/L. It can also be used for cell imaging with the biocompatibility and stability of the prepared AgNCs.2. We synthesized an efficient quencher leaf-like PpPD particals based on the chemical oxidative polymerization between AgNO3and p-phenylenediamine via PVP as a surfactant. Single strand DNA can wrap onto the surface of PpPD through the interaction of π-π stacking, while in the presence of the target, the property of effectively quenching the fluorescence disappeared. In this theory we develop a fluorescence determination of Thrombin. In the optimum condition, the fluorescence intensity of FAM have a good linear relationship with Thrombin in the range of38-226nmol/L with the linear equation of F=146+1.05c, the correlation coefficient (r) of 0.9965and the limit of determination (LOD) of15nmol/L3. Coralyne is one of protoberberine type alkaloids analogues. It was found that it could induce adenine oligonucleotides (poly A16) to form double strand DNA under quasi-physiological conditions, which cause enhanced fluorescence notably. With the increased fluorescence signals of Sybr Green I, a new enhanced fluorescence method for the determination of coralyne has been developed in a linear range of60-600nmol/L with the detection of limit (3σ) of30nmol/L. The method reported here is highly selective and other analogues have no interfering effect in the determination, and has been successfully applied to the detection of coralyne in artificial samples with the recovery from92.5%to105%, and the RSD lower than3.1%.