Nano devices fabricated from DNA and nanoparticles found many important applications in both biotechnology and nanotechnology. Conventionally, DNA was linked to gold surfaces through a linker. In this study, DNAs were directly attached to gold surfaces through S-Au bonds by modifying 5'-end of DNA with a mercapto group. The pH of the reaction mixture played an important role in DNA-gold conjugate fabrication. The DNA-Au conjugates were successfully obtained in pure forms and, with the use of this new type conjugate, Au-DNA-Au nanostructure was prepared. The Au-DNA-Au nanostructure was characterized by AFM.