An aptasensor for selective, sensitive and fast detection of lead(II) based on polyethyleneimine and gold nanoparticles

Environ Toxicol Pharmacol. 2015 May;39(3):1206-11. doi: 10.1016/j.etap.2015.04.013. Epub 2015 Apr 27.

Abstract

Lead (Pb), as a major environmental contaminant, could be harmful to humans when inhaled or ingested. In this study, we developed a sensitive, selective and fast colorimetric aptasensor for Pb(+2) based on polyethylenimine (PEI) and gold nanoparticles (AuNPs). In the absence of Pb(+2), aptamer binds to PEI. So the well-dispersed AuNPs remain stable with a wine-red color. Upon the addition of Pb(+2), a conformational change happens and a G-quadruplex aptamer/Pb(+2) complex is formed, leading to the aggregation of AuNPs and a color change to blue. This sensor showed a high selectivity toward Pb(+2) with a limit of detection (LOD) as low as 702pM. Moreover, our fabricated sensor was successfully applied for Pb(+2) detection in rat serum and tap water.

Keywords: Aptamer; Gold nanoparticles; Lead; Polyethylenimine; Sensor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aptamers, Nucleotide / chemistry*
  • Aptamers, Nucleotide / metabolism
  • Biosensing Techniques / methods
  • Colorimetry / methods*
  • Environmental Monitoring / methods
  • Gold / chemistry*
  • Lead / analysis*
  • Lead / blood
  • Limit of Detection
  • Metal Nanoparticles / chemistry
  • Models, Chemical
  • Polyethyleneimine / metabolism*
  • Rats
  • Water Pollutants, Chemical / analysis

Substances

  • Aptamers, Nucleotide
  • Water Pollutants, Chemical
  • Lead
  • Gold
  • Polyethyleneimine