The Development of Ionophore-Selective
Based optical chemical sensors for the
determination of heavy metal ions in
aqueous environments
Li, Li
(2010)
The Development of Ionophore-Selective
Based optical chemical sensors for the
determination of heavy metal ions in
aqueous environments.
PhD thesis, Dublin City University.
The development of optical sensors for in-situ, real-time and low-cost monitoring of heavy
metal ions is a tremendously and fast growing area of research. This work presents several
novel sensing strategies for developing optical chemical sensors that can be used as early
warning devices for heavy metal pollution in water.
The optical sensors that are comprised of metal chelating reagent, together with an ion
carrier immobilised within polymeric thin films, i.e. hybrid sol-gel thin films, PVC
membranes, ORMSOLs, and functionalised cellulose membranes. The developed test
strips based on 2-(5-bromo-2-2pyridydylazo)-5-diethylaminophenol (Br-PADAP)
immobilised on hybrid nafion/sol-gel membranes are capable of selectively monitoring
Ni2+ in water samples.
A novel sensing strategy, based on electrostatically immobilisation of water soluble
indicators on functionalised cationic cellulose membranes, has provided a real “green”
procedure for the fabrication of sensing materials. The promising results have been
demonstrated by the optical sensor based on Chromoazo S immobilized on cationic
cellulose membranes for the determination of Cu2+.
A novel series of double armed spirocyclic calix[4]arene compounds has been investigated
for their binding abilities with heavy metal ions. Compound 2-144 showed a good
selectivity of Pb2+ over other heavy metal ions. This compound has a potential for the use as
selective-ionophore for the development of a Pb2+ selective sensing system.