Investigation Of The Fluorescent Aptamer Sensors Assembled With The Mesoporous Nanoparticles And DNA Nanomaterials

Nano assembly technology is assembled with the nano basic units to form function structure system by mechanical,physical,chemical or biological methods.The aptamer sensors based on the nano assembly technology have been widely used in the field of biological analysis,molecular imaging,drug delivery and so on.It has played a huge role in promoting the development of life science,materials science and other fields.However,the traditional nano assembly technology was complex in design,tedious in preparation and low in versatility.In this thesis,the universal aptamer fluorescent sensors were proposed based on mesoporous nanoparticles and DNA nanomaterials.The details were summarized as follows:1.A fluorescent aptasensor for label free detection of myoglobin has been developed based on the assembled with mesoporous silica nanoparticles.First,Rhodamine 6G,a kind of small fluorescent molecules was blocked in the aptamer-capped mesoporous silica particles.In the presence of myoglobin,the aptamer left from the mesoporous surface and the fluorescence intensity was significantly enhanced after releasing Rhodamine 6G to the solution.The result showed that the concentration of myoglobin was positively associated with the fluorescence intensity of the solution.Therefore,the quantitative detection of myoglobin was achieved by monitoring the change of fluorescence intensity.Through this strategy,the limit of detection(LOD)of myoglobin was proved to be 1.1 nmol/L and with excellent selectivity.It was suggested that the method could satisfactorily meet the detection requirement of myoglobin in clinical medicine.2.A fluorescent aptasensor for the sensitive detection of myoglobin has been developed based on antibody and DNA self-assembled nanomaterials.First,The DNA self-assembled fluorescent nanomaterial was formed by HCR reaction and the interaction between biotin and avidin.In the present of myoglobin,anti-myoglobin and DNA self-assembled fluorescent nanomaterials would form a "sandwich"structure.Therefore,the quantitative detection of myoglobin was achieved by monitoring the change of fluorescence intensity.This method showed good specificity,high sensitivity.As low as 0.20 nmol/L of myoglobin was detected and the proposed method was further successfully applied to detect myoglobin in human serum samples.This method was expected to develop into a universal platform for biological detection and analysis.3.Multicolor fluorescent nanoprobes have been developed based on the DNA self-assembly.The DNA self-assembled nanoprobes were constructed with HCR,then the diffetent ratio of fluorescent dyes(FAM,TAMRA and DEA)were simultaneously incorporated into DNA nano materials via the interaction between biotin and avidin.The multicolor DNA nanocomposites were constructed based on the fluorescence resonance transfer between the fluorescent dyes and the ability of aptamer.In addition,the multicolor nanoprobes were applied to detect myoglobin and C-reactive protein.More importantly,they were also used in the cell multicolor imaging.This method was simple and it was expected to develop into a novel analysis method for multiple target detection.