Chemical Research in Chinese Universities ›› 2010, Vol. 26 ›› Issue (2): 194-197.

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Gold Nanoparticle-based Colorimetric Assay for Determination ofLead(II) in Aqueous Media

LI Xiao-kun1,2 and WANG Zhen-xin1*   

  1. 1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China;
    2. Graduate School of the Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2009-04-10 Revised:2009-04-29 Online:2010-03-25 Published:2010-05-25
  • Contact: WANG Zhen-xin. E-mail: wangzx@ciac.jl.cn
  • Supported by:

    Supported by the National Natural Science Foundation of China(No.20675080) and the Program of Chinese Academy of Sciences Hundred Talents(No.KJCX2-YW-H11).

Abstract:

The authors presented a simple colorimetric assay for the detection of toxic heavy metal lead(II) ion(Pb2+). Pentapeptide, cysteine-alanine-leacine-asparagine-asparagine(CALNN), functionalized gold nanoparticles(GNPs) were aggregated in the presence of the divalent metal ion in solution by an ion-templated chelation process, which caused an easily measurable change in the absorption spectrum of the particles. Typically, mono-dispersing GNPs exhibit an absorption band at 522 nm, corresponding to a red color solution, while aggregated GNPs have it at longer wavelengths, corresponding to a purple or blue color solution. The chelation/aggregation process is reversible via the addition of a strong metal ion chelator such as EDTA. Highly selective and sensitive detection of Pb2+ in aqueous solution is thus provided. A detection limit of 0.1 μmol/L of Pb2+ was demonstrated.

Key words: Gold nanoparticle; Peptide; Colorimetric assay; Lead(II)