Dual-enhanced SERS platform based on AuNRs@ZnO-Ov core-shell nanostructure for ultrasensitive determination of melamine in food samples

Herein, we constructed a SERS sensing platform based on a core-shell material, AuNRs@ZnO-Ov, for the detection of melamine in milk. The high Raman signal intensity can be attributed to the synergistic effect between the electromagnetic enhancement and chemical enhancement. The FDTD and molecular energy level calculations have verified the amplification of the electromagnetic field and the process of charge transfer. The AuNRs@ZnO-Ov exhibited high SERS performance with an enhancement factor (EF) of 7.08 × 10 6 , and a limit of detection (LOD) of 4.06 × 10 −8  M for melamine with good uniformity and reproducibility. Furthermore, the SERS platform delivered good linearity across a wide concentration range of 5 × 10 −8 to 5 × 10 −4  M. The proposed method has been successfully used for the detection of melamine in milk samples. This study provides a potential strategy for the construction of novel SERS substrates for molecules sensing in food.