Metallic Conduction through Engineered DNA: DNA Nanoelectronic Building Blocks

A novel way of engineering DNA molecules involves substituting the imino proton of each base pair with a metal ion to obtain $M$-DNA with altered electronic properties. We report the first direct evidence of metalliclike conduction through $15\mu \mathrm{m}$ long $M$-DNA. In contrast, measurements on $B$-DNA give evidence of semiconducting behavior with a few hundred meV band gap at room temperature. The drastic change of $M$-DNA conductivity points to a new degree of freedom in the development of future molecular electronics utilizing DNA, such as creating all-DNA junction devices for use as nanoelectronic building blocks.