Direct detection of melamine in liquid milk and infant formula using surface-enhanced Raman scattering combined with silver nanodendrites

In this report, we present the use of surface-enhanced Raman scattering (SERS) in combination with the silver nanodendrites (AgNDs) for direct detection of melamine at low concentrations in liquid milk and infant formula. The fern-like AgNDs were electrochemically deposited onto the surface of silicon. The results showed that the molecular fingerprints of melamine in liquid milk and infant formula could be directly detected with the limit of detection (LOD) as low as 0.1 mg/L in liquid milk and 0.02 mg/L in infant formula without the need for the extraction procedure. A good linear relationship between melamine SERS intensity (at 682 cm-1) and concentration of melamine in liquid milk and infant formula was obtained with the correlation coefficient (R2) reaches 0.9914 and 0.9952, respectively. These results suggest that SERS is a promising analytical method for application in food safety and environmental monitoring.