Melamine-induced aggregation of gold nanoparticles for detection of melamine

• 1、Chemistry Department, Jinan University, GuangZhou 510632
• 2、Analytical and testing center,Jinan University, Guagnzhou 510632
• 3、Chemistry Department, Jinan University, Guangzhou 510632
• 4、Chemistry Department,Jinan University,510632
• 5、Chemistry Department, Jinan University,Guangzhou 510632

Abstract：Illegal addition of melamine to milk products can threat to health. Therefore, it is important to develop a highly sensitive method that can provide the detection of melamine. A method for rapid and sensitive detection of melamine is described basing on the absorption properties of gold nanoparticles. Under medium system at pH=7, positive charged melamine adsorbs on negative charged gold nanoparticles through electrostatic interaction. The aggregated characteristics of gold nanoprticles induced by hydrogen-bonding recognition between melamine-capped gold nanoparticles can be used for sensitive detection of melamine. UV-Vis absorption spectroscopy and transmission electron microscope were used to study aggregated mechanism of nanoparticles. Under optimal condition, absorption signals of gold nanoparticles show a good linear relationship with the concentration of melamine in the range of 0.1-11.2μg/ml, a limit of detection down to 0.1μg/ml. The change in optical properties of gold nanoparticles can be directly reflected by the color change, when the concentration of melamine was above to 11.2 μg/mL. This method has some advantages of easy construction, quick detection, high sensitivity and well stability, which can be used to the detection of molecules constructed like melamine.

Keywords： gold nanoparticles UV-Vis absorption spectra melamine