▎ 摘　　要

The adsorption of DNA bases on a magnetic probe composed of Fe atoms and graphene is studied by using first-principles calculations. The stability of geometry, the electronic structure and magnetic property are investigated. The results indicate that four DNA bases, i.e., adenine, thymine, cytosine and guanine, can all be adsorbed on the probe solidly. However, the magnetic moments of the composite structure can be observed only when adenine adsorbs on the probe. In the cases of the adsorption of the other three bases, the magnetic moments of the composite structure are zero. Based on the significant change of magnetic moment of the composite structure, adenine can be distinguished conveniently from thymine, cytosine and guanine. This work may provide a new way to detect DNA bases.