He developed his research career in electrochemistry and chemical sensors at the UK Atomic Energy Research Establishment, Harwell, in the 1980s. He became Thomas Graham Professor of Chemistry at University College London in 1991 and co-founded Capteur Sensors Ltd.
He was Head of the Chemistry Dept at UCL from 1999-2002 and co-founded Aeroqual Ltd. He was Chief Scientist of Inverness Medical Innovations), based at Unipath Ltd, Bedford, UK, from 2002-2005. He joined the faculty of the Chemistry Dept at Auckland University in February 2006. He is a Principal Investigator in the MacDiarmid Institute for Advanced Materials and Nanotechnology. He is an Adjunct Professor at Dublin City University where he is a Principal Investigator in the Science Foundation Ireland-funded Biomedical Diagnostics Institute.
He is a Visiting Professor at University College London, where he has strong research links, and University of Southampton, and Honorary Professor of the Royal Institution of Great Britain, and has been Visiting Professor at University of Toronto and Cranfield University of Technology. He has published around 200 papers in international journals, and is inventor on around 40 patents.