One-step highly sensitive detection of melamine using gold nanoparticle-based dynamic light scattering

Abstract

In this paper, a dynamic light scattering (DLS)-based approach was developed for the real-time detection of melamine. Due to the strong interaction between melamine and AuNPs, the hydrodynamic diameter of AuNPs changed with increasing amounts of added melamine in the detection system, which can be directly observed by DLS. The sensitivity of this assay to detect melamine is about 0.05 ppm, and even in detection solutions with low pH values (2.5–3.5 or 4.0–5.0), this DLS-based assay can work well. All these results suggest that the DLS-based assay could be a good alternative method for one-step real-time detection of melamine, especially in complex systems (such as complex solutions with a low pH environment), without time-consuming procedures and costly instruments.