Label-free colorimetric detection of lead ions with a nanomolar detection limit and tunable dynamic range by using gold nanoparticles and DNAzyme

Zidong Wang, Jung Heon Lee, Yi Lu

Research output: Contribution to journalArticlepeer-review

Abstract

A method is presented to design a label-free colorimetric sensor based on DNAzyme for real-time detection of lead. The study used Gold nanoparticles (AuNPs) and un-labeled DNAzymes to detect lead with nanomolar detection limit and tunable dynamic range. The label free DNAzyme colorimetric sensor is based on 8-17 DNAzyme composed of a substrate strand and an enzyme strand. The DNAzyme complex was prepare in 10 mN Tris buffer pH 7.2 with 100 mM NaCl with various concentrations of lead. The sensor has a detection limit of 3nM and can be tuned by controlling the pH. The colorimetric sensors can be used to detect other metal ions and non-metal targets by using aptamers and aptazymes. The study used an UV-vis spectroscopy to investigate the plasmon resonance peak of AuNPs and found a slowness in kinetics of the reaction at lower pH.

Original languageEnglish (US)
Pages (from-to)3263-3267
Number of pages5
JournalAdvanced Materials
Volume20
Issue number17
DOIs
StatePublished - Sep 3 2008

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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