Construction And Application Of Signal Amplification Technology Based On Nanocatalyst Labeling Coupling Redox Cycling

With the development of the field of biology, the ability to detect biomolecules (DNA or Dopamine) sensitively with simple and inexpensive methods is essential in clinical diagnosis, sequence analysis, and biomedical research. Because of its low concentration, the traditional analysis methods can’t meet the needs. Developing a highly sensitive of biological sensor has become the focus of research and biochemical analysis. The amplified detection method of molecular has attracted substantial research attention. In this paper, experiment adopted the principle of catalytic hairpin assembly, redox cycling to achieve the signal amplification; we get a simple, high sensitivity, selectivity biosensor.Chapter 1, Introduction. Introduction section briefly describes some signal amplification methods, these methods can be applied to biological sensors, as well as some efficient detection methods in recent years, mainly include bio-barcode amplification, rolling circle amplification, redox cycling, et al several efficient signal amplification methods and specific application in biochemical analysis.Chapter 2, Using a simple DNA reaction mechanism based on a catalytic hairpin assembly process coupling nanocatalyst labeling. First, the target DNA can be multiple used by catalytic hairpin assembly. Second, the dsDNA was labeled with the Au@PtNPs nanocatalyst label. The electrochemical signal of low abundance target DNA was amplified through redox cycling between p-aminophenol and p-quinone imine in the presence of NaBH4, the catalytic reduction of p-aminophenol by nanocatalyst labeling. Target concentration was obtained by recording and analysis the electrochemical response signal. Combined catalytic hairpin assembly with nanocatalyst label-based redox cycling reaction achieved signal amplification, the mature method appears a broad range of concentrations from 1.0×10-18 to 1.0×10-7 mol/L with a detection limit of 3.0×10-19 mol/L for DNA detection. The regression equation is Ip= 5.010 logC+95.38,Regression coefficients is 0.9990(C, mol/L; Ip, μA)。Chapter 3, Nanoparticles labeling and graphene oxide specific adsorption of DNA signal amplification were used to detect dopamine. First, Au@PtNPs was labeled with the single-stranded DNA. Second, dopamine aptamer can bind to the dopamine and graphene oxide specific adsorb the single-stranded DNA to realize the sign amplification. Target concentration was obtained by recording and analysis the electrochemical response signal. This method provides a wide range of concentration from 1.0 X 10"13 to 1.0 ×10"5 mol/L and a detection limit of 5.0×10-14 mol/L. The regression equation is Ip= 5.280 log C+97.38, Regression coefficients is 0.9870 (C, mol/L; Ip, μA)。...