DNA-based high-density memory devices and biomolecular electronics at CSIO

Abstract

ABSTRACT During the last half century the electronic components and computers have grown more and more powerful with theshrinking dimensions of transistors which is approaching 100nm with about a billion tiny devices working togetheron a single processor. The laws of quantum mechanics and limitations of materials and fabrication techniquesrestrict further reduction below 100nm. The most promising area is Biomolecular Electronics concerning design andfabrication of basic electronic components using biomolecules. Various organic polymers are being studied forvisualization of individual molecular electronic wires and diode switches but we see enormous potential in use ofDNA for such devices due to its inherent characteristics. This is because DNA can act as insulator semiconductor,conductor or superconductor depending upon the base sequence, length and orientation. The DNA can be coatedselectively with metals with molecular level precision giving us capability to design molecular electroniccomponents, such as, diode, triode, transistor, etc.This paper discusses the DNA based language developed by our group for coding and decoding any digitalinformation in terms of DNA sequence. Basic arithmetical operations, such as, addition subtraction, multiplication,division and exponential have been defined in terms of DNA sequence and their validity has been demonstrated.Paper will also discuss our programme on study of DNA electrical behaviour in terms of sequence; length andorientation for development of biomolecular electronic components and for understanding DNA damaged chemistry. The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom byatom. It is not an attempt to violate any laws; it is something, in principle that can be done; but in practice, it hasnot been done because we are too big.You would be able to write the entire Encyclopedia Britannica on the head of a pin, with huge amounts of room tospare. You would be able to build miniature machines so small that they could manipulate at a nearly molecularscale. And you would be able to build things, atom by atom.Nobel Laureate Richard Feynman INTRODUCTIONDuring the last few years interest in molecular and self-assembled devices is growing fast to over come thelimitation of semiconductor integrated circuits and sensors. This is because semiconductor devices are approachinglimits in terms of speed and miniaturization. So we have to look for entirely new concepts. Number of approacheshave been explored e.g. quantum devices, single electron devices, carbon nanotubes and molecular devices etc. the