Programmable redox state of the nickel ion chain in DNA.

DNA is a nanowire in nature which chelates Ni ions and forms a conducting chain in its base-pairs (Ni-DNA). Each Ni ion in Ni-DNA exhibits low (Ni(2+)) or high (Ni(3+)) oxidation state and can be switched sequentially by applying bias voltage with different polarities and writing times. The ratio of low and high oxidation states of Ni ions in Ni-DNA represents a programmable multistate memory system with an added capacitive component, in which multistate information can be written, read, and erased. This study also indicates that the biomolecule-based self-organized nanostructure can be used as a template for nanodevice fabrication.