Sensor Development

In order to address concerns about the levels of various toxic gases in our environment and metal ions in our drinking water it is important to be able to measure the level of such pollutants. Therefore we need for affordable, easy to use toxic gas and water contaminant sensors. Existing technologies are typically bulky and expensive. Thin films of coloured organic molecules such as porphyrins are known to change colour upon exposure to some of these toxic materials, and have the potential to be used as small inexpensive reliable sensors. The aim of this project is to investigate the potential application of such sensing materials for a range of potential industrial and environmental applications. The PhD student will identify a range to target compounds that are of relevance e.g. NO 2 , CO, Hg 2+ , Pb 2+ etc.. . It is envisaged that the application will involve identifying a single component amongst many in a complicated mixture of gases or ions. Therefore the candidate will need to increase the sensitivity and selectivity of these sensors so it is possible to distinguish between chemically similar materials. Enhanced sensitivity will be achieved by optically triggering the sensor response and employing lock-in amplification of the sensor signal to improve the sensor signal. Enhanced selectivity will be achieved through a using an array of these sensing materials each tuned to give a slightly different response upon exposure to a different target analytes in order to develop a robust multi component sensing system by using a pattern recognition algorithm from the sensor array response.

This will predominantly be an experimental project and the student will receive training in materials characterisation, gas sensor fabrication and testing. Experimental techniques that will be used include Langmuir Schaffer deposition, scanning electron microscopy, atomic force microscopy, ellipsometry, UV-vis spectroscopy and fluorescence spectroscopy. The student will explore various different methods of enhancing selectivity of the sensors. They will attend several conferences at national and international level in order to present their work.