Preparation Of Electrochemical DNA Sensor And Detection Of Biological Small Molecule

In this article, the target DNA of bladder cancer was detected by electrochemical DNA biosensor with NaOH etched. Methylene blue (MB) was empolyed in the process of detection as hybridzation indicator. The prepared biosensor was characterized by cyclic voltammetry (CV) and differential-pulse voltammetry (DPV). As the results, the concentration of carboxyl on glassy carbon electrode (GCE) was 1.022×10-6 mol/cm2, the limit of detection (LOD) was calculated to 9.503×10-10 M, and the range of detection was from 20 to 60 nm.Graphene oxide was synthesized in aqueous phase, and characterized by FTIR, transmission electron microscope (TEM), scanning electron microscope(SEM), and XRD. An electrochemical DNA biosensor was fabricated on electroreducted graphene oxide(ERGO) and Gold nanoparticles(AuNPs) modified GCE. The single-stranded DNA (ssDNA) probe was immobilized on the surface of electrode by biological coupling agent. Methylene blue was also used in the process of detection as hybridzation indicator. The process of detection was represented by scanning electron microscopy (SEM), cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and differential-pulse voltammetry. As the results, the limit and range of detection were 6.435×10-13 M and 1×10-12 M～1×10-8M, respectively.