title: Triplex DNA logic gate based upon switching on/off their structure by Ag(+)/cysteine.
abstract: The formation of intramolecular triplex DNA can be regulated by Ag(+) and Cys (cysteine), which switch off/on the fluorescence of the oligonucleotides, 5'-TAMRA-TTC TCT TCC TCT TCC TTC TGA CGA CAG TTG ACT CTT CCT TCT CCT TCT CTT-BHQ-2-3' (Oligo 1) and 3'-GAA GGA AGA GGA AGA GAA-5' (Oligo 2). Based on this principle, sensors for Ag(+) and Cys are developed. The sensor for Ag(+) has a linear range of 2.5 nM-40 nM and a detection limit of 1.8 nM, whereas the sensor for Cys has a linear range of 10.0 nM-120.0 nM and a detection limit of 8.2 nM. Furthermore, the fluorescence is reversible with the alternate addition of Ag(+) and Cys. We constructed a DNA logic gate using Ag(+) and Cys as the input, and the fluorescence intensity as the output. The DNA logic gate is simple; moreover, it has a fast response and good reversibility.
authors.affiliation: School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China. cesllsh@mail.sysu.edu.cn.
authors.forename: Zhiyou
authors.initials: Z
authors.lastname: Xiao
authors.forename: Houya
authors.initials: H
authors.lastname: Zhu
authors.forename: Aiping
authors.initials: A
authors.lastname: Xin
authors.forename: Yubin
authors.initials: Y
authors.lastname: Li
authors.forename: Liansheng
authors.initials: L
authors.lastname: Ling
mesh_terms: D002942:Circular Dichroism / Q000379:methods; D003545:Cysteine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D008967:Molecular Biology / Q000379:methods; D009841:Oligonucleotides / Q000737:chemistry; D015203:Reproducibility of Results; D012834:Silver / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D009841:Oligonucleotides; C051802:triplex DNA; D012834:Silver; D006046:Gold; D004247:DNA; D003545:Cysteine