Jump to main content
Jump to site search

Issue 5, 2010
Previous Article Next Article

A simple, reliable and sensitive colorimetric visualization of melamine in milk by unmodified gold nanoparticles

Author affiliations

Abstract

In this paper, we report a simple, reliable and sensitive colourimetric visualization of melamine in milk products using citrate-stabilized gold nanoparticles (Au NPs). Upon exposure to ppb-level melamine, gold nanoparticle solution exhibits a highly sensitive colour change from red to blue and rapid aggregation kinetics within the initial 5 min, which can directly be seen with the naked eye and monitored by UV-vis absorbance spectra. As confirmed by the comparison with six other typical amino compounds, the melamine molecule itself contains multiple strong-binding sites to the surface of Au NPs and thus plays a role of molecular linker to efficiently crosslink Au NPs. Further evidence is that the sensitivity is significantly improved when NaHSO4 is added to promote the ligand exchange between citrate and melamine at the surface of Au NPs. The NaHSO4-optimized Au NPs system provides a rapid colourimetric assay for the rapid detection of melamine down to ∼25 ppb in real milk products.

Graphical abstract: A simple, reliable and sensitive colorimetric visualization of melamine in milk by unmodified gold nanoparticles

Back to tab navigation

Publication details

The article was received on 06 Jan 2010, accepted on 02 Feb 2010 and first published on 12 Feb 2010


Article type: Paper
DOI: 10.1039/C000285B
Analyst, 2010,135, 1070-1075

  •   Request permissions

    A simple, reliable and sensitive colorimetric visualization of melamine in milk by unmodified gold nanoparticles

    H. Chi, B. Liu, G. Guan, Z. Zhang and M. Han, Analyst, 2010, 135, 1070
    DOI: 10.1039/C000285B

Search articles by author

Spotlight

Advertisements