Suspended Ag-SiO2 composite nanopore array as SERS substrate for pyridaben detection

We develop a suspended Ag-SiO 2 composite nanopore array by a self-assembly strategy, which exhibits significant SERS effects with plenty of 3D hot spots. The Ag-SiO 2 composite nanopore array is composed of Ag nanoparticles isolated by SiO 2 , which shows strong electromagnetic coupling between discrete silver nanoparticles and along each nanopore structure, as confirmed by COMSOL simulations. SERS observations for the prepared Ag-SiO 2 composite nanopore array show an ultra-low detection limit, excellent sensitivity, high uniformity, and stability, which is successfully applied for pyridaben detection of with the detection limit 1.19 × 10 –10  M.