chemical sciences - adaptive sensors group
Adaptive Sensors Group
National Centre for Sensor Research
Dublin City University
Ph.D., Materials Science, Trinity College Dublin (2006).
B.A., Experimental Physics, Trinity College Dublin (2001).
Adaptive Polyaniline Nanostructures for Application as a Sensor Platform.
Inherently conducting polymers (ICPs) can be used in applications which exploit their tunable conductivity. Many ICPs are however unstable and degrade when exposed to atmospheric conditions. Polyaniline (PAni) is an example of a stable ICP whose conductivity can be controlled over ten orders of magnitude by changing the environment of the material. PAni switches reversibly between an insulating emeraldine base form and a conducting emeraldine salt form. PAni thus has huge potential in sensor applications. By adapting the morphology of PAni we can increase the surface area exposed to molecules which are to be detected. In this work we focus on PAni nanofibre structures which can be synthesised in a simple one-step process by interfacial polymerisation . In particular we are interested in the functionalisation of nanofibres for the detection of target species. Typically monomers can be functionalised and then subsequently polymerised to produce functionalised conductive polymers. Polymerisation using this approach can be complicated due to steric effects. Our approach is to covalently modify PAni structures post-polymerisation. This can be achieved while simultaneously maintaining the intrinsic nano-morphology of the polymer material (Figure 1). The modified PAni nanofibres can then be further adapted by attaching specific functional groups.
Using the technique developed we can demonstrate novel multifunctional materials whose properties can be externally tuned and controlled.
Figure 1: SEM (left) and AFM (right) show polyaniline nanofibres have a uniform diameter in the region of 80nm.
 J. Huang, R.B. Kaner, J. Am. Chem. Soc., 2004, 126, 851.
1. E. Lahiff, C.Y. Ryu, S. Curran, A.I. Minett, W.J. Blau, P.M. Ajayan. Selective Positioning and Density Control of Nanotubes within a Polymer Thin Film. Nano Letters (Communication), 3(10), 1333-1337, 2003.
2. E. Lahiff, A.I.Minett, S. Curran, C.Y. Ryu, W.J. Blau, P.M. Ajayan. Controlling the Position and Morphology of Nanotubes Within a Polymer Thin Film. Mat. Res. Soc. Symp. Proc., Vol. 782, A5.11.1, 2003.
3. E. Lahiff, R. Leahy, A.I. Minett, W.J. Blau. Controlling the Position and Morphology of Nanotubes for Device Fabrication, AIP Proc. Vol 723(1), 544-547, 2004.
4. E. Lahiff, A.I. Minett, W.J. Blau. Manipulation and Direction of Conduction Channels through a flexible carbon nanotubes thin film composite. Int. Conf. Synth. Met. Proc., 2004.
5. R.W. Leahy, E. Lahiff, A.I. Minett, W.J. Blau. Controlled Growth of Arrays of Straight and Branched Carbon Nanotubes, Proc. SPIE (Int. Soc. Opt. Eng.), 5824, 62, 2005.
6. E. Lahiff, R. Leahy, J.N. Coleman, W.J. Blau. Physical properties of novel free-standing polymer–nanotube thin films. Carbon, 44(8), 1525-1529, 2006.
7. Rory W. Leahy, Emer Lahiff, A.I. Minett, W.J. Blau. Chemical Vapour Deposition Grown Nanotubes for Interconnect Technology. Journal of Nanotechnology Online, Vol. 3, 2007. (DOI: 10.2240/azojono0121)
8. Emer Lahiff, Kentaro Nakajima, A.I. Minett, W.J. Blau. Producing controlled Grid Patterns of Nanotube Arrays for Strengthening Polymer Composites. Journal of Nanotechnology Online, Vol. 3, 2007. (DOI: 10.2240/azojono0125
9. Lahiff, E., Bell, S., Diamond, D., Functionalised Nanostructured Polyaniline – A New Substrate for Building Adaptive Sensing Surfaces. Mater. Res. Soc. Symp. Proc. 2008, 1054, 1054-FF05-05
10. Lahiff, E.; Woods, T.; Blau, W.; Wallace, G. G.; Diamond, D., Synthesis and characterisation of controllably functionalised polyaniline nanofibres. Synthetic Metals 159 (2009), 741-748.
11. E. Lahiff, S. Scarmagnani, B. Schazmann, A. Cafolla, D. Diamond. Controllable attachment of funtional side-groups to Polyaniline Nanofibres. International Journal of Nanomanufacturing, Vol. 5, Nos. ½ (2010).
12. E. Lahiff, C. Lynam, N. Gilmartin, G. Wallace, R. O’Kennedy, D. Diamond. Controllable Chemical Modification of Polyaniline Nanofibres. Mater. Res. Soc. Symp. Proc. 2009, 1240-WW06-02.
13. E. Lahiff, C. Lynam, N. Gilmartin,R. O’Kennedy, D. Diamond. The Increasing Importance of Carbon Nanotubes and Conducting Polymers in Biosensors. Journal of Analytical and Bioanalytical Chemistry. 2010, 398(4), 1575-89.
14. C. Lynam, E. Lahiff, N. Gilmartin,D. Diamond, R. O’Kennedy,. Antibody Functionalised Polyaniline Nanofibres.Synthetic Metals. Accepted.
1. ‘Embedded Nanotube Array Sensor and Method of Making a Nanotube Polymer Composite’. Applicants: P.M. Ajayan, E. Lahiff, P. Stryjek, C.Y. Ryu, S. Curran. Patent No. 7,673,521. Granted 03/09/2010
Enterprise Ireland - Proof of Concept, 2008, €76,000.
SFI - Conferences and Workshop Award, 2009, €5,000.
DCU - Conferences and Workshop Award, 2009, €1,600.
Jan-May 2009: Temporary lecturer, School of Physical Sciences, DCU.
Jan-Dec 2006: Research Scientist, Materials Ireland Polymer Research Centre, Trinity College Dublin.
Aug-Dec 2005: Physics Tutor, D.I.T. Bolton Street, Dublin 1.
May 2005: Visiting Scientist, Max Planck Institute for Solid State Physics, Stuttgart, Germany. Worked in Nobel Laureate Prof. von Klitzings department.
Aug 2001- Dec 2002: Visiting Scholar, Department of Materials Science & Engineering, Rensellaer Polytechnic Institute, New York, USA. Worked under the supervision of Prof. Ajayan.
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