title: Colorimetric detection of potassium ions using aptamer-functionalized gold nanoparticles.
abstract: Herein, a simple and novel colorimetric method for detection of potassium ions (K(+)) was developed. The colorimetric experiments revealed that upon the addition of K(+), the conformation of anti-K(+) aptamer in solution changed from random coil structure to compact rigid G-quadruplex one. This compact rigid G-quadruplex structure could not protect AuNPs against K(+)-induced aggregation, and thus the visible color change from wine-red to blue-purple could be observed by the naked eye. The linear range of the colorimetric aptasensor covered a large variation of K(+) concentration from 5 nM to 1 μM and the detection limit of 5 nM was obtained. Moreover, this assay was able to detect K(+) with high selectivity and had great potential applications.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing 100048, China. czb979216@sina.com
authors.forename: Zhengbo
authors.initials: Z
authors.lastname: Chen
authors.forename: Yanqin
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Li
authors.forename: Tong
authors.initials: T
authors.lastname: Zhou
authors.forename: He
authors.initials: H
authors.lastname: Ma
authors.forename: Hong
authors.initials: H
authors.lastname: Qiang
authors.forename: Yifei
authors.initials: Y
authors.lastname: Liu
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011188:Potassium / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D011188:Potassium
keywords: Aptamer; Colorimetric detection; Gold nanoparticle; Potassium ion