Synthesis, characterization, and performance evaluation of polyamide‐Ag@SiO2 Raman substrate

At present, Ag nanoparticles have been widely used as Raman substrates, but their easy oxidation and aggregation have limited practical applications. In order to address the above problems, firstly, tetraethyl orthosilicate as a precursor was applied to synthesis silver coated with silica dioxide nanoparticles (Ag@SiO 2 ). As a result, the surface of Ag nanoparticles is uniformly coated with a thin layer of SiO 2 in order to solve the easy oxidation problem without adversely affecting their surface‐enhanced Raman scattering (SERS) performance. Furthermore, Ag@SiO 2 nanoparticles were electrostatically deposited onto polyamide (PA) films to form a two‐dimensional PA‐Ag@SiO 2 film substrate, thus resolving nanoparticle agglomeration issues and further improving the repeatability of the entire system. As can been from the SERS detection results obtained from the probe molecules and pollutants, the Raman signal on the PA‐Ag@SiO 2 thin film substrate has a good degree of sensitivity, stability, and repeatability.