Nanoelectronics: Tunneling current in DNA–Single electron transistor

Modern silicon-integrated circuit technology has been undoubtedly increasing computing speed every 18 to 24 months according to Moor’s prediction and further, reduction in feature dimensions is not possible without various quantum problems. Despite the fabrication of the molecular junctions (acting as quantum dots), and a CNT field-effect transistor, it is very difficult to connect a single molecule to external leads, thus preventing verification of this idea until recently. Individual molecules can perform functions identical to those of the key components of present day microcircuits. Molecular engineering extends its potential application to manufacture electronic devices at nano scale with much more sophisticated advantages over the modern day microelectronics. The reason behind forming molecular electronics may be that the society at large has a demand for smaller, faster, simpler and better technologies. Bio-electronics is one of the areas of interest that overlaps with biotechnology and includes DNA electronics and cellular computing. Electronic circuit components using single molecules have been proposed since 1974. DNA-based electronic components such as single electron transistors are also being proposed and realized. In this paper, we present the possible tunneling current under different external biasing conditions. DNA–SET model is based on tunneling properties of P-bonds (as tunneling junctions in coulomb blockade regime) in sugar–phosphate backbones of single-strand DNA molecules.