The preparation and surface enhanced Raman Scattering spectroscopy of AuNRs@ZIF-8

Surface enhanced Raman spectroscopy (SERS) is a kind of molecular spectrum, which has the characteristics of rapidity, high sensitivity and fingerprint recognition, and has important applications in analytical chemistry, biomedicine and other fields. However, some detection molecules in the solution sample are difficult to be adsorbed by the SERS substrate, resulting in difficulty in enhancing the Raman signal of molecular. To this end, this paper proposes a core-shell structure (AuNRs@ZIF-8) of ZIF-8 material coated gold nanorods (AuNRs) to achieve Raman signal enhancement. Both the surface plasmon enhancement characteristics of the gold nanoparticles and the adsorption properties of ZIF-8, a porous MOFs material, can be used to realize highly sensitive Raman detection of the solution samples. We first prepare the well-homogeneous AuNRs by seed crystallization method, then modify them with polyvinylpyrrolidone (PVP), and finally add the metal-organic framework ZIF-8 precursor to obtain the AuNRs@ZIF-8 Core-shell nanostructures. The structure has high sensitivity to the SERS detection of rhodamine (R6G), the detection limit can be as low as 10⁻⁹ M, and the linear relationship and homogeneity are good. In addition, we further confirm the formation of the core-shell nanostructures and effective adsorption of the target molecules by testing the UV-Vis absorption spectra of the structure before and after R6G absorption.