title: An aptasensor for detection of potassium ions based on RecJ(f) exonuclease mediated signal amplification.
abstract: An electrochemical biosensor for potassium has been developed combining specific potassium-aptamer binding and RecJf exonuclease mediated signal amplification. Generally, the DNA probe with a stem-loop structure containing an anti-K(+) aptamer sequence is designed and modified on a gold electrode. K(+) can specifically bind to the aptamer and a G-quadruplex structure forms, which breaks the original stem-loop structure. The induced single-stranded 5' end can be further digested by RecJf exonuclease, releasing K(+) which can bind to another DNA probe on the electrode. After cycles of RecJf exonuclease cleavage initiated by K(+), the electrochemical signal intensity is significantly decreased, and can be used to determine the concentration of K(+). This aptasensor shows high sensitivity, selectivity as well as excellent stability and accuracy, which provides possibilities for further applications of K(+) assay in clinical diagnosis.
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. miaopeng@sibet.ac.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Miao
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Tang
authors.forename: Bidou
authors.initials: B
authors.lastname: Wang
authors.forename: Kun
authors.initials: K
authors.lastname: Han
authors.forename: Xifeng
authors.initials: X
authors.lastname: Chen
authors.forename: Haixuan
authors.initials: H
authors.lastname: Sun
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis*; D005092:Exonucleases / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D011188:Potassium / Q000032:analysis* / Q000652:urine
chemical_list: D052157:Aptamers, Nucleotide; D005092:Exonucleases; D011188:Potassium