title: Label-free fluorescent aptasensor for potassium ion using structure-switching aptamers and berberine.
abstract: A simple, rapid and label-free fluorescent aptasensor was fabricated for the detection of potassium ion (K(+) ion) in aqueous solution using K(+) ion-stabilized single stranded DNA (ssDNA) with G-rich sequence as the recognition element and a fluorescent dye, berberine, as the fluorescence probe. In the presence of K(+) ion, the G-rich ssDNA is promoted to form the aptamer-target complex with a G-quadruplex conformation, and berberine binding to the G-quadruplex structure results in the enhancement of its fluorescence. The fluorescence intensity of the sensing system displayed a calibration response for K(+) ion in the range of 0-1600μM with a detection limit of 31nM (S/N=3) and a relative standard deviation (RSD) of 0.45%. This label-free fluorescence aptasensor is conveniently and effectively applicable for analysis of K(+) ion in blood serum samples with the recovery range of 81.7-105.3%. The assay for detection of potassium ion is easy, economical, robust, and stable in rough conditions.
authors.affiliation: Department of Chemistry, Jinzhong University, Jinzhong, Shanxi 030600, PR China; Institute of Environmental Science, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, PR China.
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Institute of Environmental Science, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, PR China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institute of Environmental Science, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, PR China. Electronic address: weiyanli@sxu.edu.cn.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Institute of Environmental Science, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, PR China.
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Environmental Science, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, PR China. Electronic address: dc@sxu.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001599:Berberine / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000032:analysis / Q000737:chemistry; D005453:Fluorescence; D054856:G-Quadruplexes; D007477:Ions / Q000032:analysis; D015394:Molecular Structure; D011188:Potassium / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D007477:Ions; D001599:Berberine; D011188:Potassium
keywords: Aptasensor; Berberine; Fluorescence; Label-free; Potassium ion; Structure-switching