title: Ultrasensitive DNA detection by cycle isothermal amplification based on nicking endonuclease and its application to logic gates.
abstract: In recent years, an intense interest has grown in the DNA logic gates having high potential for computation at literally the "nano-size" level. A limitation of traditional DNA logic gates is that each target strand hybridizes with only a single copy of the probe. This 1:1 hybridization radio limits the gain of the approach and thus its sensitivity. The exponential amplification of nucleic acids has become a core technology in medical diagnostics and has been widely used for the construction of DNA sensor, DNA nanomachine and DNA sequencing. It would be of great interest to develop DNA-based logic systems with exponential amplification for the output signal. In the present study, a series of three-input DNA logic gates with the cycle isothermal amplification based on nicking endonuclease (NEase) are designed. Very low concentrations of the analytes were sufficient to initiate an autocatalytic cascade, achieving a significant improvement of the detection limit, 100-fold improvement compared to the non-autocatalytic system. This was achieved by engineering a simple and flexible biological circuit designed to initiate a cascade of events to detect and amplify a specific DNA sequence. This procedure has the potential to greatly simplify the logic operation because amplification can be performed in "one-pot".
authors: State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China. xuemei_li@yeah.net
authors: Xuemei
authors: X
authors: Li
authors: Tianrong
authors: T
authors: Ding
authors: Li
authors: L
authors: Sun
authors: Changming
authors: C
authors: Mao
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D039301:Computers, Molecular; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D053904:DNA Breaks, Single-Stranded; D003850:Deoxyribonuclease I / Q000737:chemistry*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013696:Temperature
chemical_list: D004247:DNA; D003850:Deoxyribonuclease I