title: Light-assisted synthesis of Pt-Zn porphyrin nanocomposites and their use for electrochemical detection of organohalides.
abstract: Pt-Zn porphyrin nanocomposites have been synthesized using zinc porphyrin and dihydrogen hexachloroplatinate in the presence of light and ascorbic acid. TEM and AFM imaging revealed that Pt nanoparticles with an average diameter of approximately 3.5 nm were embedded within the Zn porphyrin matrix. The glassy carbon electrode was modified with Nafion-stabilized Pt-Zn porphyrin nanocomposites and used for dehalogenation of carbon tetrachloride, chloroform, pentachlorophenol, chlorobenzene, and hexachlorobenzene as five test models. The Pt-Zn porphyrin nanocomposite-modified electrode exhibited catalytic activity for the reduction of organohalides at -1.0 V versus Ag/AgCl. Raman signatures confirmed the dehalogenation of chlorobenzene by the nanocomposite-modified electrode. The above two aliphatic and three aromatic organohalides had detection limits of 0.5 microM with linearity up to 8 microM. The modified electrode was good for at least 80 repeated measurements of 4 microM chlorobenzene with a storage stability of 1 month at room temperature. The deactivation of the electrode activity was associated with the loss of platinum nanoparticles from the nanocomposite structure.
authors.affiliation: Biotechnology Research Institute, National Research Council Canada (NRCC), Montreal, Quebec, Canada, H4P 2R2.
authors.forename: Wisitsree
authors.initials: W
authors.lastname: Wiyaratn
authors.forename: Sabahudin
authors.initials: S
authors.lastname: Hrapovic
authors.forename: Yali
authors.initials: Y
authors.lastname: Liu
authors.forename: Werasak
authors.initials: W
authors.lastname: Surareungchai
authors.forename: John H T
authors.initials: JH
authors.lastname: Luong
mesh_terms: D004563:Electrochemistry; D004566:Electrodes; D006219:Halogens / Q000032:analysis*; D008027:Light; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D011166:Porphyrins / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects*; D015203:Reproducibility of Results; D013057:Spectrum Analysis; D015032:Zinc / Q000737:chemistry*
chemical_list: D006219:Halogens; D011166:Porphyrins; D010984:Platinum; D015032:Zinc