Model Calculations Of Molecular Logic Gates Nucleic Acids

Look back60years, the first electronic general-purpose computer was created by the University of Pennsylvania. Since then, electronic computer began to grow rapidly and changed people’s life greatly. However, because computers have own Physical limits, Scientists found it very difficult to solve several calculation problems, like a NP-problem. Some scientists are beginning to look for the next generation of computers. One of the options for future computer is a molecular Computer due to chemical molecules and bio-molecule based on nanometer scale. Molecular computing is the foundation of a molecular computer. Molecular computing belongs to Interdisciplinary Study. Specifically, it would depend on research progress in Molecular Biology, System Biology, Organic Chemistry, Computer Science, Electrical and Electronics Engineers. Silicon-based integrated circuits are essentially combination of electronic logic gates. Nucleic acid molecules are brilliant biochemical engineering materials, because of their biological nature supports technological applications in vivo,their easy chemical synthesis facilitates practical experiments in vitro, and what’s more, Watson-crick complementarity principle can predict the behavior of the molecules. Based on these features, nucleic acid molecules have become powerful tools in molecular computing. In the long-term, Silicon-based integrated circuits will most likely be replaced with nucleic acid molecules for future computer.This thesis focuses on the design and research of molecular logic gates based on nucleic acid. It refers strictly to reproducing the process of electronic logic gates by nucleic acid, constructing well-universal components, increasing the feasibility to construct large-scale molecular circuits. In this paper, following is an overview:(1) This article mainly discusses research work about three core areas for molecular computing, namely, traditional computing、Turing machine computing and logic circuits computing. It’s impossible for the rapid development of molecular computing and its theoretical molecular computers without multiple-discipline crossing. Although rarely large-scale molecular circuit (logic gates,101-1000) have been constructed in vitro, the establishment of molecular circuit looks like remote, similarly to silicon-based electronic circuit complexity. Once basic principles for the design of logic gates are established by scientists, they would synthetic molecules circuit by the nanoscale devices in vitro, which may be connected to molecule circuit in vivo. This will promote the further development of Computing Science, including artificial intelligence and brain-computer interface.(2) Electronic circuit is based on silicon logic gate,8various combinations are commonly used in electronics for two-input logic gates, namely, OR, AND, XOR, INH, NOT, NOR, NAND XNOR gate. Molecular circuit is based on molecular logic gate. The central dogma of molecular biology explains the relationship between DNA, RNA, and proteins. This article mainly discusses eight types of molecular logic gates based on DNA, and more complex components including adder(half-adder, half-subtractor, half-full adder) and set-reset latches. This proves that it is entirely possible to construct basic logic gates by DNA molecules. However, from electronic logic gates point of view, this seems still inadequate. Firstly, molecular logic gates are varied, the format of inputs and outputs isn’t the same type. Secondly, It’s very difficult to occur cascade reaction for the next step even expands molecules circuit. Scientists still need to find better universal basic logic components.(3) DNA strand displacement technology is "star" in molecules circuit in the scientists’eyes. But it is used dynamic nanotechnology earlier in the molecular circuit earlier than molecular circuit. Peptide nucleic acid (PNA) is an artificially synthesized molecule similar to nucleic acid molecules. This article mainly constructs the new logic gates-INH gate and Implication gate, based on the basic principle of strand displacement and PNA (Peptide nucleic acid) technology. This will add a new logical operator model to molecule circuit by strand displacement, in order to provide an idea for obtaining larger molecular circuit.(4) Both Molecular beacon (MB) and gold nanoparticle technology are proven technology. However, in recent years, some scientists have combined two technologies, and beginning some research work in the field of molecular computing. Here, we report the construction of a novel molecular beacon (MB)-based nucleic acid logic gates model (OR gate, AND gate), which regarded oligonucleotides as input signal and fluorescence detection as an output signal, moreover, the traditional organic dyes (quenching agents) were replaced with a more sensitive gold nanoparticles (quenching agents), furthermore, using two-color nanoscale MB was raised in the AND gate structure, distinguished with one-colored in the OR gate. We also construct a novel molecular "half-subtractor" model with branch migration principle of strand displacement. Half-subtractor is more complex logic component, this will provide important support for the next small or large-scale molecular circuit.