Multilayer assemblies of polyelectrolyte-gold nanoparticles for the electrocatalytic oxidation and detection of arsenic(III).
Multilayers of poly(diallyldimethylammonium chloride) (PDDA) and citrate capped Au nanoparticles (AuNPs) anchored on sodium 3-mercapto-1-propanesulfonate modified gold electrode by electrostatic layer-by-layer assembly (LbL) technique are shown to be an excellent architecture for the direct electrochemical oxidation of As(III) species. The growth of successive layers in the proposed LbL architecture is followed by atomic force microscopy, UV-vis spectroscopy, quartz crystal microbalance with energy dissipation, and electrochemistry. The first bilayer is found to show rather different physico-chemical characteristics as compared to the subsequent bilayers, and this is attributed to the difference in the adsorption environments. The analytical utility of the architecture with five bilayers is exploited for arsenic sensing via the direct electrocatalytic oxidation of As(III), and the detection limit is found to be well below the WHO guidelines of 10ppb. When the non-redox active PDDA is replaced by the redox-active Os(2,2'-bipyridine)(2)Cl-poly(4-vinylpyridine) polyelectrolyte (PVPOs) in the LbL assembly, the performance is found to be inferior, demonstrating that the redox activity of the polyelectrolyte is futile as far as the direct electro-oxidation of As(III) is concerned.
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.
M M
MM
Ottakam Thotiyl
Hajra
H
Basit
Julio A
JA
Sánchez
Cedric
C
Goyer
Liliane
L
Coche-Guerente
Pascal
P
Dumy
S
S
Sampath
Pierre
P
Labbé
Jean-Claude
JC
Moutet
D001151:Arsenic / Q000032:analysis*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D011095:Polyethylenes / Q000737:chemistry*; D058525:Quartz Crystal Microbalance Techniques; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; D014867:Water; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D006046:Gold; D001151:Arsenic