Study On The Three Kind Of Electrochemiluminescence DNA Biosensor

Now many major diseases are serious threat to human health, such as infectious disease, hereditary diseases and cancer. And these disease early prevention, timely diagnosis and treatment are dependent on drug and gene detection. The aim of this thesis is to design and fabricate three kinds of ECL DNA biosensors for the determination of immunology analysis with high sensitivity and selectivity, has important significance for some of the tumor timely discovery and early diagnosis. Main contents as follows:In Chapter1, general introduction to DNA biosensor, aptamer biosensor and hairpin biosensor, including their classification, application, research development, the purpose of this research work and contents were presented.In Chapter2, consists of two parts:the first part is about studies of a novel ECL biosensors for label-free determination of BLMs. For BLMs as a model analyte, the ECL biosensors were fabricated by immobilizing Ru(phen)32+onto a gold electrode surface via electrostatic binding.when Fe(II)-BLMs can identify5’-GC/T-3’site and cut off, the ECL signal changed. The ECL intensity was linearly related to the concentration of BLMs in the range from0.1to10pmol·L-1with a detection limit of0.03pmol·L-1.The biosensor is label-free and offers a sensitive method for BLMs detection. And the other is about electrogenerated chemiluminescence DNA-based bio sensing switch for the determination of bleomycin. By studies on an chemiluminescence DNA biosensor based on gold nanoparticle-labeled DNA probe, it was designed on basis of special stem-loop with hairpin DNA and a structure-switching ECL-dequenching mechanism. The ECL intensity versus the concentration of BLMs was linear in the range from5.0×10-15to5.0×10-12mol·L-1.The detection limit was2×10-15mol·L-1. The method has higher sensitivity and lower detection limit.In Chapter3, electrogenerated chemiluminescence method for detection of DNA methylation and assay of the methyltransferase activity.The decrement of integrated ECL intensity is proportional to the concentration of M.SSSI in the range from0.05to100U/mL, the detection limit as low as0.02U/mL M.SSI was achieved. This method has the advantages of high sensitivity, simple and rapid.