Fano resonances of organic films on asymmetric split-ring resonators (A-SRRs)

Thin organic films deposited on the surface of arrays of asymmetric split-ring resonators (A-SRRs) produces a shift in their resonance spectra that can be utilised for sensitive analyte detection. When poly-methyl-methacrylate (PMMA) a well known electron beam lithography resist, is used as an organic probe, the phase and amplitude of a characteristic molecular Fano resonance associated with a carbonyl bond changes with its position relative to spectra peaks of the A-SRRs. The localization of blocks of PMMA at different positions on the A-SRR array also shows their relative sensitivity to position and corresponding hot spots as determined by simulation. Other organic materials such as progesterone show similar Fano resonances.