Preparation And Evaluation Of Aptamer Bonding Organic Polymeric Monoliths

Nucleic acid aptamers have been paid more and more attention due to their high specificity and selectivity for the target and high stability,good repeatability and easy chemical modification.In this paper,two matrix columns of different structures with epoxy groups on the surface were prepared by in-situ thermal initiated polymerization.The aptamers of terminal modified amino groups were immobilized on the prepared organic polymer column by post-column modification,and thus two functional organic polymer monolithic columns bonding nucleic acid aptamers have been presented for the specific recognition of Ochratoxin A(OTA).The main contents are listed as follows:In chapter 1,literature review.In this part,the classification and research progress of capillary affinity monolith was introduced,and the characteristics of nucleic acid aptamer and its immobilization technology were summarized.And then,the basis and scheme for special recognication of OTA of this study was put forward.In chapter 2,based on a stationary phase with epoxy functional group prepared by glycidyl methacrylate(GMA)as functional monomer and ethylene glycol dimethacrylate(EDMA)as crosslinking agent,an organic polymer monolithic column poly(Aptamer-GMA-co-EDMA)was produced by bonding nucleic acid aptamer.The composition,mechanical stability,structure and morphology of monolithic column were investigated.The changes of the electroosmotic flow,infrared spectroscopy and the polarity of the stationary phase of the poly(Aptamer-GMA-co-EDMA)were also explored.Through optimizing the conditions for column derivatization of nucleic acid aptamers and recognition efficiency of target OTA,the prepared poly(Aptamer-GMA-co-EDMA)column showed a good characteristic of specific recognition for OTA.In chapter 3,by using methacrylate epoxy cyclosiloxane(epoxy-MA)with three epoxy groups in an eight-membered ring structure as the functional monomer,an organic polymerized monolithic column was prepared.Then,a novel monolithic column of poly(Aptamer-epoxy-MA-co-EDMA)was fabricated by post-column modification of 5'-amino acid aptamer.Various factors including polymerization composition,structure morphology,mechanical stability and reproducibility of the monolith were investigated in detail.Several characteristics such as electrochromic flow,infrared spectrum and the change of the surface polarity were characterized to compare the differences among poly(epoxy-MA-co-EDMA)matrix column,diol-column formed through hydrolysis reaction and aptamer-bonded column.The prepared poly(epoxy-MA-co-EDMA)structure was stable and the surface epoxy amount of the stationary phase was larger than that of the GMA matrix.The parameters such as the concentration of aptamers modified,enrichment concentration of OTA and elution conditions,have been also investigated to estimate the selective recognition ability of nucleic acid aptamers.The prepared poly(Aptamer-epoxy-MA-co-EDMA)column can selectively identify OTA with the coexistence of ochratoxin B and aflatoxin B1.The specific recognition of OTA in poly(Aptamer-epoxy-MA-co-EDMA)column was significantly higher than that of other aptamer columns combined random DNA.The recognition of OTA is efficient and specific.