Gold Nanoparticle-Based Sensing of "Spectroscopically Silent" Heavy Metal Ions

Youngjin Kim, Robert C. Johnson, Joseph T. Hupp

Research output: Contribution to journalArticle

270 Citations (Scopus)

Abstract

A simple colorimetric technique for the detection of small concentrations of aqueous heavy metal ions, including toxic metals such as lead, cadmium, and mercury, is described. Functionalized gold nanoparticles are aggregated in solution in the presence of divalent metal ions by an ion-templated chelation process; this causes an easily measurable change in the absorption spectrum of the particles. The aggregation also enhances the hyper-Rayleigh scattering (HRS) response from the nanoparticle solutions, providing an inherently more sensitive method of detection. The chelation/aggregation process is reversible via addition of a strong metal ion chelator such as EDTA. Suggestions for improving the sensitivity and selectivity of the technique are given.

Original languageEnglish
Pages (from-to)X-167
JournalNano letters
Volume1
Issue number4
Publication statusPublished - Apr 1 2001

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ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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