An antisymmetric plasmon resonance in coupled gold nanoparticles as a   sensitive tool for detection of local index of refraction
  A nanofabricated regular array of coupled gold nano-pillars is employed to detect local indices of refraction of different liquids using a shift of an antisymmetric plasmon resonance peak observed in the reflection spectra. The peak spectral position is found to be a unique function of the local refractive index for a wide range of indices. We discuss possible applications of the fabricated nanostructured arrays in bio and chemical sensors. 
A. N. Grigorenko, H. F. Gleeson, Y. Zhang, N. W. Roberts, A. R.   Sidorov, A. A. Panteleev