Plasmonic properties and sensor application of the Ag nanocaps

Plasmonic properties of the Ag nanocaps were analyzed by the finite-difference time-domain method, in addition to the fabrication and sensor application of the two-dimensional Ag nanocap arrays. The thickness limitation for the light penetration of the nanocaps was revealed. The evolution of the plasma modes with the shell thickness and structure of the nanocaps was illustrated. The hemisphere nanocap was found to own the strongest absorption intensity and field enhancement. The sensing ability of the fabricated Ag hemisphere nanocap arrays was evaluated by the Raman spectrum of the rhodamine 6G and methylene blue molecules. The ordered arrays displayed improved light absorption with intense plasmon coupling, resulting in the strong surface-enhanced Raman scattering with an enhanced factor 15 folds of the nanosphere arrays, which suggested that the metal nanocaps might be promising for biochemical sensor application.

Automated summary

The research analyzed the plasmonic properties of silver nanocaps and their effects in fabrication and sensor applications, revealing the thickness limitation for light penetration and the evolution of plasma modes with structural changes. Hemisphere nanocaps were found to have the strongest absorption intensity and field enhancement. Additionally, the ordered arrays displayed improved light absorption and strong surface-enhanced Raman scattering, making the metal nanocaps promising for biochemical sensor applications.