title: Electrochemical detection of aqueous Ag+ based on Ag+-assisted ligation reaction.
abstract: In this work, a novel strategy to fabricate a highly sensitive and selective biosensor for the detection of Ag(+) is proposed. Two DNA probes are designed and modified on a gold electrode surface by gold-sulfur chemistry and hybridization. In the presence of Ag(+), cytosine-Ag(+)-cytosine composite forms and facilitates the ligation event on the electrode surface, which can block the release of electrochemical signals labeled on one of the two DNA probes during denaturation process. Ag(+) can be sensitively detected with the detection limit of 0.1 nM, which is much lower than the toxicity level defined by U.S. Environmental Protection Agency. This biosensor can easily distinguish Ag(+) from other interfering ions and the performances in real water samples are also satisfactory. Moreover, the two DNA probes are designed to contain the recognition sequences of a nicking endonuclease, and the ligated DNA can thus be cleaved at the original site. Therefore, the electrode can be regenerated, which allows the biosensor to be reused for additional tests.
authors.affiliation: 1] CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China [2] University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Miao
authors.affiliation: 1] CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China [2] University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Han
authors.affiliation: CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China.
authors.forename: Bidou
authors.initials: B
authors.lastname: Wang
authors.affiliation: CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China.
authors.forename: Gangyin
authors.initials: G
authors.lastname: Luo
authors.affiliation: CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China.
authors.forename: Mingli
authors.initials: M
authors.lastname: Chen
authors.affiliation: 1] CAS Key Lab of Bio-Medical Diagnostics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, P. R. China [2] University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Tang
mesh_terms: D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver