Highly selective colorimetric detection of hydrochloric acid using unlabeled gold nanoparticles and an oxidizing agent

Suraj Kumar Tripathy, Ju Yeon Woo, Chang-Soo Han

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36 Citations (Scopus)


We report a colorimetric system for the detection of HCl in aqueous environments using unlabeled gold nanoparticle (AuNP) probes. This nonaggregation-based detection system relies on the ability of chloro species to cause rapid leaching of AuNPs in an aqueous dispersion containing a strong oxidizing agent, such as HNO 3 or H 2O 2. The leaching process leads to remarkable damping of the surface plasmon resonance peak of the AuNP dispersion. This method works only with AuNPs of a particular size (∼30 nm diameter). It is highly selective for HCl over several common mineral acids, salts, and anions. This simple and cost-effective sensing system provides rapid and simple detection of HCl at concentrations as low as 500 ppm (far below the hazard limit) in natural water systems.

Original languageEnglish
Pages (from-to)9206-9212
Number of pages7
JournalAnalytical Chemistry
Issue number24
Publication statusPublished - 2011 Dec 15


ASJC Scopus subject areas

  • Analytical Chemistry

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