Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560487 | Talanta | 2011 | 6 Pages |
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 -NH2 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 (A650/A520) of the modified GNPs in the NaCl-optimized system exhibited a linear correlation with melamine concentration and the limit of detection is 8Â nM, well below the safety limit (1Â ppm for infant formula in China).
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Haichao Su, Hai Fan, Shiyun Ai, Na Wu, Hongmin Fan, Pengcheng Bian, Jianchao Liu,