Influence of silver-nanoparticle layer in a chiral sculptured thin film for surface-multiplasmonic sensing

摘要

Multiple surface-plasmon-polariton (SPP) waves can be guided by the interface of a metal and a chiral sculptured thin film (STF). It is possible to embed within the chiral STF a layer of silver nanoparticles as sites to bind recognition molecules for sensing analytes of a certain kind. Chiral STFs were deposited on aluminum thin films. 5-nm-thick layers of silver nanoparticles were deposited in the chiral STF at different depths in different samples. The samples were then deployed in the Turbadar-Kretschrnann-Raether configuration to observe the effects the silver-nanoparticle layer had on the multiple SPP-wave modes in relation to the depth. We concluded that the silver-nanoparticle layer tends to shift the angular locations of the SPP-wave modes but does not necessarily affect the location of the SPP-wave modes to an extent that would render the data uninterpretable.