Highly sensitive SERS performance and excellent durability of the ZIF-67@Ag/TiN composite films substrate

The ZIF-67@Ag/TiN composite films were synthesized by in situ growth method and used as a noble substrate for surface enhanced Raman spectroscopy (SERS). The composition, morphology, optical properties and SERS performance of the composite films were characterized. The XRD, SEM and EDS results show that face-centered cubic TiN crystal, face-centered cubic Ag crystal and ZIF-67 triple-phase material was formed in the films. The ZIF-67 nanoparticles have an orthorhombic structure with a diameter of about 500 nm, which gives the composite films porous structure and might adsorb more probe molecules. The ZIF-67@Ag/TiN composite films have superior Raman enhancement performance with a detection limit of 10 –12 M and an enhancement factor of 8.71 × 10 7 for the probe molecule R6G. In addition, the ZIF-67@Ag/TiN composite films have good homogeneity and long-term stability.