Plasmonic nanoantenna arrays hold promise for ultrasensitive sensors

The breakthrough has been made by researchers at the Universities of Bristol and Bedfordshire in collaboration with ABB.

The arrays, designed and tested by Dr Neciah Dorh during his PhD at Bristol University, are made from aluminium nanorods fabricated using electron beam lithography by commercial partner Kelvin Nanotechnologies. At 50nm wide and 158nm long, the nanorods are designed to resonantly enhance fluorescence emission from contaminants in water including diesel or tryptophan.

The work, published in Applied Optics, is said to show a six-fold increase in measured fluorescence emission from a dye. The research also shows that by correctly designing the array element spacing, strongly directional fluorescent emission can be obtained which would allow for highly integrated multi-wavelength sensors to be designed.

The work was carried out in Prof Martin Cryan’s research group, which is part of the Photonics Research group in the Department of Electrical and Electronic Engineering at Bristol University. Prof Cryan obtained funding from ABB as part of the ABB research grant programme.