Development of Optical Sensors for the Determination of Heavy Metal Ions In Aqueous EnvironmentLi LiSupervisor: Fiona ReganNCSR, School of Chemical Science, Dublin City University
Project Summary • Start date: October 2006 • End date: December 2009 This research program is to design sensors based on novel materials capable of interacting selectively with a specific metal ion in aqueous solution.
Background • What are Optical Chemical Sensors? • Why is it attractive? • Applications • Advantages over Traditional technologies • Large Market Potential…
Potential benefits/exploitation … Optical Chemical Sensors can be used anywhere by anyone … Simple Design, Low-cost, Reliable Measurement, Green Fabrication,
Plasticized PVC lipophilic anion centre R-. HM Diffusion Complexation HM HM HM HM HM HM HM HM HM HM HM HM HM HM HM aq. After Before Plastic/glass support Platform Chromoionophore Sensing Membrane
Materials study for Colorimetric Optode • Sol-gel
Commercially Available Chromophores • Advantages: • High molar absorption coefficient • Cheap • High Formation Constant, Rapid response • For total metal ions measurements • Disadvantages: • Unselective for specific metal ions • pH sensitive • Irreversible Br-PADAP Figure 1.Spectrum showing response of sol-gel sensor (a) sol-gel at t=0 min (b) t= 10 min at pH 7.5 for Nickel (II).
Investigation of Novel Calixrene compounds for their binding abilities with varies heavy metal ions • Introduction
Ligand-Metal Binding study by Pederson’s Method Figure 1. Binding propeties of ligands by Liquid-liquid extraction method.
Optode for Metal Ions Speciation-Fe (II) vs Fe (III), Cr (III) vs Cr (VI) • Acid Alizarin Violet N for Iron Speciation • For Chromium Speciation Cr2O72- + DPC Cr3+ + DPCO
Conclusion • Progress made to date • Development of simple-use test trips based on commercially available Chromophores; • Investigation of Calixrene compounds for their binding abilities with varies heavy metal ions; • Materials study for Colormetric Optode; • Optode for Metal Ions Speciation. • Implications for project outcomes • No Changes to project .
Acknowledgement • Financial support of QUESTOR Research Centre. • Dr Fiona Regan for her encouragement and inspiration. • Dr Mary Deasy, James Wards, Fintan Kelleher for their synthesis of calixarene compounds. • My colleagues and technical staffs in DCU. Thanks for your attention!