title: Layer-by-layer assembly of electroactive dye/inorganic matrix film and its application as sensor for ascorbic acid.
abstract: A novel inorganic-organic composite ultrathin film was fabricated by layer-by-layer assembly of naphthol green B (NGB) and layered double hydroxides (LDHs) nanoplatelets, which shows remarkable electrocatalytic behavior for oxidation of ascorbic acid. LDHs nanoplatelets were prepared using a method involving separate nucleation and aging steps (particle size: 25±5 nm; aspect ratio: 2-4) and used as building blocks for alternate deposition with NGB on indium tin oxide (ITO) substrates. UV-vis absorption spectroscopy and XRD display regular and uniform growth of the NGB/LDHs ultrathin film with extremely c-orientation of LDHs nanoplatelets (ab plane of microcrystals parallel to substrates). A continuous and uniform surface morphology was observed by SEM and AFM image. The film modified electrode displays a couple of well-defined reversible redox peaks attributed to Fe(2+)/Fe(3+) in NGB (ΔE(p)=68 mV and I(a)/I(c)=1.1). Moreover, the modified electrode shows a high electrocatalytic activity towards ascorbic acid in the range 1.2-55.2 μM with a detection limit of 0.51 μM (S/N=3). The Michaelis-Menten constant was calculated to be K(M)(app)=67.5 μM.
authors.affiliation: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Xianggui
authors.initials: X
authors.lastname: Kong
authors.forename: Wenying
authors.initials: W
authors.lastname: Shi
authors.forename: Jingwen
authors.initials: J
authors.lastname: Zhao
authors.forename: Min
authors.initials: M
authors.lastname: Wei
authors.forename: Xue
authors.initials: X
authors.lastname: Duan
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis*; D002384:Catalysis; D004396:Coloring Agents; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D006878:Hydroxides; D057230:Limit of Detection; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D010316:Particle Size; D013499:Surface Properties
chemical_list: D004396:Coloring Agents; D006878:Hydroxides; D008567:Membranes, Artificial; D001205:Ascorbic Acid