Abstract: Au@PVP core-shell nanoparticles were prepared by the hydrothermal method. Benzidine molecules were absorbed onto the surface of Au@PVP core-shell nanoparticles through the hydrogen bonding interaction between benzidine and polyvinylpyrrolidone (PVP). Benzidine molecules could be highly sensitively detected by the electromagnetic enhancement effect of the inner-core Au nanoparticles under the optimal excitation wavelength and the appropriate pH value. The limit of detection (LOD) was 10-9 mol/L, which was nearly 103 times lower than the limit of detection of the gas chromatography (GC) method for surface drinking water described in the Environment Quality Standards for Surface Water.

Key words: Au@PVP core-shell nanoparticle, benzidine, surface-enhanced Raman scattering (SERS)