Design of DNA-based innovative computing system of digital comparison

Despite great potential and extensive interest in developing biomolecule-based computing, the development of even basic molecular logic gates is still in its infancy. Digital comparator (DC) is the basic unit in traditional electronic computers, but it is difficult to construct a system for achieving large-scale integration. Here, we construct, for the first time, a novel logic computing system of DCs that can compare whether two or more numbers are equal. Our approach is by taking advantage of facile preparation and unique properties of graphene oxide and DNA. The DC system reported in this work is developed by the DNA hybridization and effective combination of GO and single-stranded DNA, which is regarded as the reacting platform. On the basis of this platform and reaction principle, we have developed 2-inputs, 3-inputs, and 4-inputs DCs to realize the comparison of two or more binary numbers. We predict that such a state-of-the-art logic system enables its functionality with large-scale input signals, providing a new direction toward prototypical DNA-based logic operations and promoting the development of advanced logic computing. STATEMENT OF SIGNIFICANCE: The overarching objective of this paper is to explore the construction of a novel DNA computing system of digital comparator driven by the interaction of DNA and graphene oxide (GO). GO can efficient bind the dye-labeled, single-stranded DNA probe and then quench its fluorescence. In the case of the target appearing, specific binding between the single-stranded probe and its target occurs, changing the conformation and relationship with GO, then restoring the fluorescence of the dye. We have developed the 2-inputs, 3-inputs, and 4-inputs digital comparator circuits, which are expected to realize the comparison of large-scale input signals and can avoid the problems of design complexity and manufacturing cost of integrated circuits in traditional computing.