A rapid method for the determination of methionine (Met) based on the anti-aggregation of gold nanoparticles (AuNPs) in serum and urine is presented. Melamine (Mel) can induce the aggregation of AuNPs through the ligand exchange between amine groups on melamine and negatively charged citrate ions and then induce color change of the AuNPs solution from wine red to blue. However, the AuNPs is more prone to combining with Met through both AuS and AuN bonds in the presence of Mel, which hinders the aggregation of AuNPs induced by Mel. A good linear correlation (R² = 0.996) between absorbance ratio and the Met concentration is obtained over the range from 0 μM to 1.0 μM. The detection limit was estimated as low as 24.5 nM and the recovery of Met added to serum and urine samples was 95.0-105% and 95.0-104%, respectively. The result represents that the method makes this sensor promising for the applications in the development of detecting Met.

提出了一种基于金纳米颗粒（AuNPs）在血清和尿液中抗聚集的快速测定甲硫氨酸（Met）的方法。三聚氰胺（Mel）可通过三聚氰胺上的胺基与带负电荷的柠檬酸根离子之间的配体交换诱导AuNP聚集，然后诱导AuNPs溶液从酒红色变为蓝色。然而，在Mel存在下，AuNP更易于通过Au S和Au N键与Met结合，这阻碍了由Mel诱导的AuNP的聚集。良好的线性相关性（R ² 在0μM至1.0μM的范围内获得的吸光度比与Met浓度之间的比值= 0.996）。估计检出限低至24.5 nM，添加到血清和尿液样品中的Met回收率分别为95.0-105％和95.0-104％。结果表明，该方法使该传感器在检测Met的开发中具有广阔的应用前景。