Electrochemical Biosensor Based on Dendrimer Immobilized Deoxyribonucleic Acid

A novel DNA electrochemical biosensor was prepared by immobilizing the first generation polyamidoamine (G1 PAMAM) dendrimer on the glassy carbon electrode (GCE) surface by coupled activation agent, which was treated via electrochemical oxidation. Using methylene blue as the indicator, the DNA electrochemical biosensor was characterized by cyclic voltammetry and differential pulse voltammetry. The results indicated that the complementary ssDNA segment in the solution could be recognized and detected through mensurating the oxidation- deoxidation peaks current of embed methylene blue in dsDNA. The linear range for the determination of target DNA is from 2 × 10−9 to 2 × 10−7 M, and the detection limit is 1 × 10−9 M.