DNA Logic Circuits Based on Accurate Step Function Gate

DNA molecular as the material for logical computing and information storage has been widely applied. An important mechanism for DNA logical computing is the toehold-mediated DNA Strand Displacement (DSD). Researchers have used the DSD mechanism and designed various DNA circuits to perform logical computing processes. However, the logy reaction speed in some logic gates limited the speed of response, the output response is not sensitive enough. Therefore, no output response is often misjudged to logic “0”, high output response is not accurate to logic “1”. In this paper, we proposed a highly creditable step function gate, which consists of a step function module and a threshold module. The output signal in this proposed gate is highly sensitive and accurate to logic “0” & “1”. The proposed gate can recognize the difference between “no input” and “low input”. Besides, we built the OR, AND, NOT, XOR circuits by the proposed step function gate, and the simulation results are highly supported.