Ni(2+) doping DNA: a semiconducting biopolymer.

DNA is a one-dimensional nanowire in nature, and it may not be used in nanodevices due to its low conductivity. In order to improve the conducting property of DNA, divalent Ni(2+) are incorporated into the base pairs of DNA at pH≥8.5 and nickel DNA (Ni-DNA) is formed. Conducting scanning probe microscopy (SPM) analysis reveals that the Ni-DNA is a semiconducting biopolymer and the Schottky barrier of Ni-DNA reduces to 2 eV. Meanwhile, electrochemical analysis by cyclic voltammetry and AC impedance shows that the conductance of Ni-DNA is better than that of native DNA by a factor of approximately 20-fold. UV spectroscopy and DNA base pair mismatch analyses show that the conducting mechanism of Ni-DNA is due to electrons hopping through the π-π stacking of DNA base pairs. This biomaterial is a designable one-dimensional semiconducting polymer for usage in nanodevices.