Colorimetric detection of potassium ions using aptamer-functionalized gold nanoparticles

Anal Chim Acta. 2013 Jul 17:787:189-92. doi: 10.1016/j.aca.2013.05.020. Epub 2013 May 21.

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.

Keywords: Aptamer; Colorimetric detection; Gold nanoparticle; Potassium ion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Colorimetry / methods
  • Gold / chemistry*
  • Metal Nanoparticles / chemistry*
  • Potassium / analysis*
  • Spectrophotometry, Ultraviolet / methods

Substances

  • Aptamers, Nucleotide
  • Gold
  • Potassium