Background

Analysis of drinking water is generally done using mass spectrometry techniques, taking up to a few days for results to be returned from laboratories. Whilst being extremely accurate and reliable, mass spectrometry methods are laboratory based, and require time.

There is a need for rapid identification of potentially dangerous concentrations of contaminants in water using in situ equipment. The drinking water inspectorate (DWI) and European regulations are placing increasing regulation onto the water industry, potentially creating a significant market for low cost, simple to use, in situ and fast techniques to test water.

The technology

The technique developed at Sheffield Hallam University involves the use of planar wave guide 'sandwiches', with an SiO2 layer between two Si3N4 layers. Laser light is directed into the wave guide, and some of this is refracted through an enzyme active thin film. The amount of attenuation of laser light gives a highly sensitive indication of the presence of heavy metals such as lead and inorganic chemicals in a water sample. A patent has not yet been filed, however there is patentable material in aspects of the technology.

Benefits

The benefits of the planar wave guide system are that results can be obtained in five to 10 minutes, and the technique is highly sensitive, detecting lead in concentrations of less than 10ppb. It would be a low cost product to make, involving a small briefcase sized kit, and simple to use, as it does not require a qualified operative and it could be operated on a mobile basis, including on site at water storage and transport facilities.

Development stage

A development partner is needed to upscale the technology from the laboratory to a prototype product.

Lead researcher(s)

Dr Alexei Nabok