Design Of Multi-input Modular Circuit Based On DNA Strand Displacement

Limited by Moore's law,the development of traditional physical computing has encountered a bottleneck.More and more scientists have been exploring novel methods of calculation.DNA computing,with its remarkable advantages of parallel computation,large energy storage,low energy consumption and intelligent biological experiments,has become one of the hot research directions in the field of biology.DNA strand displacement technology takes an important part of DNA computing,which is not only applied to construct simple biochemical circuits,but also increasingly looks towards to large-scale,multi-input and multimodular complex circuits.Based on DNA strand displacement technology,sixteen-input encoder and four-bit carry ahead adder molecular circuits and reaction modules are designed.The main research contents are as follows:Aiming at the problems of high complexity,difficult cascading of molecular chains in DNA strand displacement reaction and few studies on multi-input encoders,a molecular logic circuit based on sixteen-input encoder of DNA strand displacement reaction is built.The circuit is simulated and verified in DSD,the simulation results of which obtain the expected results.In this paper,the modular design of the sixteen-input encoder molecular circuit aims to solve the problem of difficult cascading and high complexity of DNA circuits to a certain extent.At the same time,it provides a reference for the construction of large scale modular molecular circuits.Aiming at the problem that the traditional adder calculates step by step and the carry affects each other,it results in low output efficiency and high error rate.In this paper,based on the traditional adder,the molecular circuit of the four-bit forward carry adder is designed.In most cases of the designed molecular circuit,all carry numbers are generated at the same time.In addition,there is no influence between adjacent carry.It gets rid of the problem of mutual influence between traditional adder carry.The accuracy of the circuit is verified by software,which also shows that the molecular circuit constructed in this paper has higher calculation efficiency and lower error rate.The design of this paper is truly solving the mathematical problem from the biological point of view,and provides a method for solving more complicated mathematical problems.Aiming at the problems of unsynchronized DNA strand displacement reaction,complicated circuit construction and poor circuit transplantability,based on the principle of DNA strand displacement reaction and reversible reaction,four basic chemical reaction modules of catalysis,degradation,annihilation and synchronization are designed.The function of the designed module is verified in DSD.The four chemical reaction modules are applied to the oscillator to achieve the synchronization of the input and output of the oscillator.In addition,The modularization design of complex circuits increases the stability and portability of the circuits,and provides theoretical support for the construction of multi-level synchronization and complex module circuits.In this paper,a multi-input modular circuit design is realized by DNA strand displacement technology,including a sixteen-input encoder and four-bit carry ahead adder molecular circuit design.The response module is used to synchronize the input and output of the oscillator.The content studied in this paper provides a reference for constructing more complex circuits with more inputs,more outputs,and more modules.