EPSRC logo

Details of Grant 

EPSRC Reference: GR/S96845/01
Title: Understanding the gas sensing behaviour of porphyrin
Principal Investigator: Richardson, Dr TH
Other Investigators:
Barford, Professor W Hunter, Professor CA
Researcher Co-Investigators:
Project Partners:
T Q Environmental Plc
Department: Physics and Astronomy
Organisation: University of Sheffield
Scheme: Standard Research (Pre-FEC)
Starts: 15 November 2004 Ends: 14 November 2007 Value (£): 241,481
EPSRC Research Topic Classifications:
Chemical Structure Materials Processing
Materials Synthesis & Growth
EPSRC Industrial Sector Classifications:
Electronics Environment
Related Grants:
Panel History:  
Summary on Grant Application Form
Porphyrins offer a useful way of detecting and monitoring ultra-low concentrations of various toxic and polluting gases and vapours In the 0.05 (50 ppb) - 5.0 parts per million range. Their interaction with certain analytes (eg. N02 gas) leads to adsorption-Induced optical transitions which can be tracked in situ during exposure to the analyte. The half-life (t50 response time) is of the order of a few seconds and the optical absorbance of thin films of certain porpyrins changes by as much as 80% upon exposure to - 1 ppm N02. Their further development depends upon identifying the mechanism through which the optical changes occur and upon designing specific porphyrins and thin film architectures that facilitate easy access of the analyte to the sensitive binding sites within the porphyrin macrocycles. This programme therefore focuses on the development of colourimetric porphyrin thin film gas sensing materials for the detection and monitoring of low concentrations of both certain inorganic gases (such as N02, CI2 and HCI) and certain organic vapours (such as chloroform, toluene and methanol).Quantum chemical calculations of the excited states of porphyrin molecules with and without adsorbed analytes will be performed with the alms of establishing the origins of the adsorption-induced optical transitions and determining the energies and oscillator strengths of these transitions as a function of the analyte and the specific porphyrin substituent side-groups. This modelling will allow us to identify what specific optical changes occur in relation to specific analytes and as a result should allow us to design sensing materials which are selective to particular analytes for which there is a great need to detect.An ambitious synthesis programme coupled to thin film processing and sensor evaluation stages of the research will identify novel porphyrin sensing materials whose electronic properties are highly sensitive to low levels of the above gases and vapours. This investigation will lead to an understanding of the relationships between the detailed chemical structure / film architecture and the gas-sensing performance, thus paving the way for the design, synthesis and processing of optimised materials which are capable of the specific recognition of certain gases.The sensing behaviour of these materials will be studied in terms of gas sensitivity, response and recovery rate and stability to temperature, time and humidity. Collaboration with our industrial partner - TO Environmental plc - will enhance our testing facilities and ensure that commercial and technological inputs to the project are accommodated
Key Findings
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Potential use in non-academic contexts
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Description This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Date Materialised
Sectors submitted by the Researcher
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Project URL:  
Further Information:  
Organisation Website: http://www.shef.ac.uk