Selective determination of melamine in milk samples using 3-mercapto-1-propanesulfonate-modified gold nanoparticles as colorimetric probe.

Abstract

A novel and sensitive colorimetric method for determination of melamine in milk samples was developed by a 3-mercapto-1-propanesulfonate-modified gold nanoparticles (MPS-GNPs) probe. Melamine molecule has multiple -NH(2) groups. These functional groups can interact with MPS to form strong hydrogen bonding and induce the aggregation of the MPS-GNPs, resulting in a dramatic color change from red to blue. Therefore, the concentration of melamine in milk samples can be quantitatively detected by the naked eyes or a UV-vis spectrometer. Moreover, investigations have revealed that the sensitivity of the detection could be clearly improved by adding NaCl to the modified GNPs solution, which leads to a more rapid color change in the NaCl-optimized GNPs system. It is worth noting that the absorption ratio (A(650)/A(520)) of the modified GNPs in the NaCl-optimized system exhibited a linear correlation with melamine concentration and the limit of detection is 8 nM, well below the safety limit (1 ppm for infant formula in China).

DOI: 10.1016/j.talanta.2011.06.017

Cite this paper

@article{Su2011SelectiveDO, title={Selective determination of melamine in milk samples using 3-mercapto-1-propanesulfonate-modified gold nanoparticles as colorimetric probe.}, author={Haichao Su and Hai Ming Fan and Shi-yun Ai and Na Wu and Hongmin Fan and Pengcheng Bian and Jianchao Liu}, journal={Talanta}, year={2011}, volume={85 3}, pages={1338-43} }