Monopole antenna arrays for optical trapping, spectroscopy, and sensing

We introduce a nanoplasmonic platform merging multiple modalities for optical trapping, nanospectroscopy, and biosensing applications. Our platform is based on surface plasmon polariton driven monopole antenna arrays combining complementary strengths of localized and extended surface plasmons. Tailoring of spectrally narrow resonances lead to large index sensitivities (S similar to 675 nm/RIU) with record high figure of merits (FOM similar to 112.5). These monopole antennas supporting strong light localization with easily accessible near-field enhanced hotspots are suitable for vibrational nanospectroscopy and optical trapping. Strong optical forces (350 pN/W/mu m(2)) are shown at these hotspots enabling directional control with incident light polarization. (C) 2011 American Institute of Physics. [doi:10.1063/1.3559620]