title: Photoelectrochemical determination of inorganic mercury in aqueous solutions.
abstract: An analytical method using an optical probe in a photoelectrochemical cell for the sensitive and selective determination of aqueous Hg(2+) is presented. A previously synthesized Hg(2+) selective chemosensor, proven to be Hg(2+) sensitive up to 2 microg L(-1), has been immobilized onto indium tin oxide (ITO) electrodes in a composite form with polyaniline. The coated ITO electrode was placed in a photoelectrochemical cell under closed circuit conditions in which the optical recognition of the chemosensor was converted to a measurable signal. A composite of the fluorescent chemosensor, Rhodamine 6G derivative (RS), and polyaniline (PANI) was immobilized on ITO glass plates and subjected to photovoltage measurements in the absence and presence of Hg(2+). The optical responses of the coated electrode were used to determine the sensitivity and selectivity of the immobilized sensor to Hg(2+) in the presence of background ions. The optical response of the PANI-dye coated electrode increased linearly with increasing Hg(2+) concentration in the range 10-150 microg L(-1), with a detection limit of 6 microg L(-1).
authors.affiliation: Department of Chemistry and Polymer Science, University of Stellenbosch, Matieland X1, Stellenbosch 7602, South Africa.
authors.forename: Jessica
authors.initials: J
authors.lastname: Chamier
authors.forename: Joy
authors.initials: J
authors.lastname: Leaner
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Crouch
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D004784:Environmental Monitoring / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry*; D007204:Indium / Q000737:chemistry; D008628:Mercury / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D017971:Tin Compounds / Q000737:chemistry; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D017971:Tin Compounds; D014874:Water Pollutants, Chemical; D007204:Indium; D014867:Water; D008628:Mercury; C045358:stannic oxide