Hydrogen-bonding-induced colorimetric detection of melamine by nonaggregation-based Au-NPs as a probe.
A colorimetric, label-free, and nonaggregation-based gold nanoparticles probe has been developed for the detection of melamine. Gold nanoparticles were generated using 3,5-dihydroxybenzoic acid as a reducer without adding gold nanoparticle seeds at room temperature. Upon the addition of melamine, the reducer 3,5-dihydroxybenzoic acid can interact with melamine through strong hydrogen-bonding interaction. Consequently, the formation of gold nanoparticles was interrupted by melamine since there was not enough reducer for the reduction of Au(3+) ion. And the color change from purple to yellowgreen with increasing melamine concentration was observed. The plasmon absorbance of the formed Au-NPs allows the quantitative detection of melamine. A sensitive linear correlation existed between the absorbance and the logarithm of melamine concentration ranging from 1x10(-9) M to 1x10(-5) M with a linear coefficiency of 0.993. The system has a high selectivity to melamine with a low detection limit of 8x10(-10) M.
Cao
Qian
Q
College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, Beijing, China.
Zhao
Hong
H
He
Yujian
Y
Li
Xiangjun
X
Zeng
Lixi
L
Ding
Nan
N
Wang
Jian
J
Yang
Jie
J
Wang
Guangwei
G
D003124:Colorimetry / Q000379:methods*; D005506:Food Contamination / Q000032:analysis; D006046:Gold; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D062385:Hydroxybenzoates; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D019163:Reducing Agents; D012118:Resorcinols; D017550:Spectroscopy, Fourier Transform Infrared; D020349:Surface Plasmon Resonance / Q000379:methods*; D014227:Triazines / Q000032:analysis* / Q000737:chemistry
D062385:Hydroxybenzoates; D019163:Reducing Agents; D012118:Resorcinols; D014227:Triazines; C076950:alpha-resorcylic acid; D006046:Gold; C011907:melamine