Graphene /Cu-Ag composites were prepared by a simple stirring reduction procedure. A novel electrochemical sensor was developed based on graphene /Cu-Ag composites modified glassy carbon electrode. The as-prepared graphene /Cu-Ag composites were characterized by scanning electron microscope and transmission electron microscope. The electrochemical behaviors of guanine and adenine on the modified electrode were investigated by cyclic voltammetry and differential pulse voltammetry. The results showed that the...