1. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Ionic Liquids – Inherent sensing and transduction of metal ion complexation EMRS Spring Meeting Strasbourg, France 10 th June 2010

2. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Me.. Graduated with B.Sc (Hons) in Chemical & Pharmaceutical Sciences, Dublin City University (2008). PhD. in “Ionic Liquids and their use in the development of potential chemical sensors”. Sept 08’ Supervisors Dr. Aleksandar Radu & Prof. Dermot Diamond

3. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Outline Ionic Liquids Polymeric Optodes Ionic Liquid – PVC Optodes UV/Vis Characterisation Alternate Detection Techniques Wireless Radio Frequency Detection Electrochemical Impedance Spectroscopy Portable X-Ray Fluorescence

4. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Ionic Liquids Unique combination of ions that are liquid at room temperature Choice of ion pair can have dramatic impact on Density Viscosity Miscibility with Solvents

5. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Applications Synthesis & Catalysis in Organic Chemistry => Good thermal stability Electrochemistry => Good Conductivity and a large electrochemical window Analytical Chemistry => Stable stationary phase for separations

6. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Polymeric Optodes Typically contain up to 5 components Polymer Inert matrix to house active sensing components Plasticizer Lowers T g of polymer to produce solid film Ion-Exchanger Facilitates Ion Transfer from aq. to organic phase Ionophore Selectively binds ion of interest Transducer Dye Produces optical response 3. A. Radu, R. Byrne, N. Alhashimy and D. Diamond, Abstr. Pap. Am. Chem. Soc., 2006, 231, 41-INOR. PMMA optodes containing Spiropyran dye

7. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Cu 2+ /Co 2+ Co 2+ Cu 2+ Simple, 2-component optodes [P 6,6,6,14 ][DCA] acts as plasticizer ion-exchanger ligand transducer dye Upon exposure to Cu 2+ and Co 2+

8. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Multianalyte Recognition

9. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Binding Constants Best fit was found to be 2M for 1L

10. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Dicyanamide Pseudohalide, shown in literature to bind to an array of TM elements 1 Due to strong electron delocalisation across molecule, resulting in a variety of binding modes 2 Rich binding diversity results in many 1,2 and 3-D co-ordinated networks reported Used to impart low viscosity in a new generation of Ionic Liquids 1. S. R. Batten, P. Jensen, B. Moubaraki, K. S. Murray and R. Robson, Chem. Commun., 1998, 439-440. 2. S. R. Batten and K. S. Murray, Coordination Chemistry Reviews, 2003, 246, 103-130. M DCA

11. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Interference Spectra 4. J. Kohout, L. Jager, M. Hvastijova and J. Kozisek, J. Coord. Chem., 2000, 51, 169-218. Ni 2+ has been shown to bind to DCA 4, yet produces no optical response

12. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE RF Wireless Conductivity Detection In conjunction with CSIRO Laboratories, Melbourne, Australia Works by passing low voltage, low frequency AC signal from transmitting to receiving electrodes Sample is housed in an insulating container Conductive sample produces a signal as it passes through the electrode field

13. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE RF Wireless Conductivity Detection Depending on pH, polyaniline (PAni) can switch between conductive and non-conductive forms Ink-jet printed Pani dispersion Strip housed in insulating container Response occured upon repeated exposure to acetic acid and ammonia N. B. Clark and L. J. Maher, Reactive & Functional Polymers, 2009, 69, 594-600.

14. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Conductive Membranes WRF has the required sensitivity to distinguish between complexed and non-complexed membranes “Edge effects” occur as insulating material first enters and leaves electrode channel Membrane Group:Ionic LiquidCopperMixCobalt PVC: IL (1:2)52486.1439292.6640267.7543479.93 PVC: IL (1:1)15879.977068.519428.3014908.19 PVC: IL (2:1)7502.650.00

15. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Screen Printed Electrodes Ag/AgCl ink used as conducting path Carbon Paste used as working electrode Insulating Layer defines the working area Conducting polymer (Poly (3-octylthiophene)) is first dropcast to aid ionic to electronic Transition PVC-IL cocktail dropcast and allowed to dry A. Morrin, A. J. Killard and M. R. Smyth, Analytical Letters, 2003, 36, 2021-2039.

16. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Impedance Spectroscopy PVC:IL 1:2 (w/w) PVC:IL (1:1 w/w)

17. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Portable X-Ray Fluorescence Emitting x-rays knocks out electron in inner shell Vacancy is filled by atom from outer shell Filling of vacancy emits frequency XRF picks up frequency characteristic of element

18. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE XRF Results Used to quantify [DCA] - binding preferentiality Co levels were found to be 45% lower Even as a mixture (2:1 Co:Cu (vol.)) Co levels are 88% lower! MembraneCopper:Cobalt:MixtureBlank Composition:Copper:Cobalt:Copper:Cobalt: 1. PVC:IL (1:1 w/w) 2642.14 (165.73) 1207.55 (153.38)2551.91 (164.43) 272.17 (83.39) 80.98 (21.56) 69.59 ( 168.57) 2. PVC:IL (1:2 w/w) 16996.25 (424.75) 7652.11 (371.17)12866.82 (357.98) 1559.59 (179.21) 192.55 (81.51) < LOD 3. PVC:IL (2:1 w/w) 222.53 (77.79) < LOD 294.12 (90.91) 202.62 (88.09) < LOD

19. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Conclusions The Ionic Liquids [P 6,6,6,14 ][DCA] fulfils multiple roles in polymeric optodes Conductive membranes allow for detection via an array of techniques The relative ease of synthesis and diversity allows for the possibility of new IL’s with greater selectivity

20. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Acknowledgements Dr’s. Aleksandar Radu, Robert Byrne and Professor Dermot Diamond Michele Zanoni, Bartosz Ziolkowski, Larisa Florea and Caroline Barry Dr’s. Noel Clarke and Matthius Hilder at CSIRO Cytec Industries DCU Research Career Start Fellowship 2008 Science Foundation Ireland (grant 07/CE/I1147) Enterprise Ireland (grant 07/RFP/MASF812)

21. UNIVERSITY COLLEGE DUBLIN  DUBLIN CITY UNIVERSITY  TYNDALL NATIONAL INSTITUTE Thanks for listening!