The sensors, which use plasmonic nanoantenna arrays, could lead to the development of a new generation of ultrasensitive and low-cost fluorescence sensors that could be used to monitor water quality.

The arrays are made from aluminium nanorods fabricated using electron beam lithography, and are designed to resonantly enhance fluorescence emission from a range of contaminants in water such as diesel or tryptophan.

The project was a collaboration between Bedfordshire and the University of Bristol.

The research, published in Applied Optics, shows 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.

Dr Tahmina Ajmal, a Senior Lecturer in Engineering from Bedfordshire’s School of Computer Science & Technology, said: “The nanoantenna arrays enhance the emission of fluorescence which can be used to detect very low levels of a contaminant in water. This makes them an ideal choice for use in an early warning system in open water sources. Early detection of pollution will help stop the spread of the contamination and resolve further problems.”

Professor Martin Cryan from the Department of Electrical & Electronic Engineering at the University of Bristol, said: “The nanoantenna arrays, which can be fabricated by lower cost production techniques such as nanoimprint lithography, can bring significant sensitivity enhancement so that laboratory quality measurements could be carried out in the field. This would allow for deployment of remote wireless sensor networks for early warning of pollution or continuous monitoring of water quality in sensitive environments.”