From fano to nano: mechanisms and applications of surface enhanced raman spectroscopy

This is complemented by experimental far-field and numerical data. It is concluded that plasmon mixing is involved in an unexpectedly high SERS enhancement in samples with relatively low nanostructure packing density and that the positions of the respective ‘isolated’ and ‘system’ resonances, along with coupling degree and relative linewidth, may be projected via a classical analogue of coupled oscillators. In a subsequent study, leaning gold-covered silicon nanopillars are analysed where plasmonic interference and ‘substrate-solution hydrophobic effects’ are provided as explanations for the magnitudes and patterns of SERS enhancements observed via numerical studies.

This is alongside a more conventional numerical investigation into dimer systems with nanometric-sized gaps. Very small inter-dimer separations (< 2 nm) or even a degree of coalescence are favoured. Finally, detecting explosive precursors is explored as part of a large European consortium: ‘Bomb Factory Detection by Networks of Advanced Sensors.’ Via a novel chemical derivatisation approach, nitric acid is detected via SERS down to 100 ppb with ppt range projected.