Improved adsorption of choline oxidase on a polyelectrolyte LBL film in the presence of iodide anionsстатья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:This study describes the effects of F−, Cl−, Br−, and I− anions on the sensitivity of a biosensor assembled via layer-by-layer deposition of poly(diallyldimethylammonium chloride) (PDDA) and choline oxidase (ChO) on the surface of a graphite electrode coated with MnO2. A four-fold increase in sensitivity of the MnO2/PDDA(KHal)/ChO biosensor was observed when the adsorption of the PDDA layer was carried out from the solution containing I− in a narrow range of concentrations (20–30 mM). According to AFM and SEM data, spatial distribution of the enzyme and gold nanoparticles (Au-NPs) on the surface varied with the conditions of PDDA adsorption. A fine-grain film was observed when PDDA was adsorbed from the solution containing Cl−, whereas association of ChO or Au-NPs into larger domains took place in the case of I− solution. Absorption spectra of Au-NPs adsorbed on a PDDA(KI) film evidenced aggregate formation as well. A schematic representation of the enzyme layer assembly was proposed for different ionic conditions of the polyelectrolyte pre-adsorption.