Investigating the plasmonic behaviour of gold nanostructured arrays with finite element method modelling for optical sensing applications

The small array spacing may be difficult to fabricate so an array with nanorods of 20x150nm and spacing of 60nm may be more viable. <br><br>Simulations showed field enhancements within the nanostructured array, which could be utilised for plasmon-enhanced fluorescence (PEF) to amplify the signal from fluorescent molecules. Integration of chips into a well plate produced an easy to use setup within readily available microplate readers in diagnostic laboratories.

Chips were characterised, and then modelled to simulate field enhancement factors for comparison to experimental data. Enhancement factors of 2-5 were in good agreement with most experimental values, however some chips had increased experimental enhancement factors of around 20. <br><br>The simulation work completed shows how surface properties, including fabrication defects and array coupling, affect the electromagnetic behaviour of the novel nanorod array surface.

While the results help to improving fundamental knowledge of plasmonic interactions, simulated plasmonic spectra and local field enhancements can also be used to guide fabrication for a range of LSP applications. Additionally, the surface has been shown to be a feasible sensing platform for diagnostic applications, with in-situ monitoring through the tabletop LSPR device or through the initial PEF setup.