Enhanced electrochemistry of nanoparticle-embedded polyelectrolyte films Interfacial electronic coupling and distance dependence

Factors affecting the electronic communication believed to be responsible for the enhanced solution electrochemistry observed at electrodes modified with hybrid polyelectrolyte-nanoparticle (PE-NP) film assemblies were systematically investigated Specifically the faradaic current and voltammetric peak splitting recorded for cyclic voltammetry of ferricyanide redox species (Fe(CN)(6)(3-/4-)) at films constructed with various architectures of citrate-stabilized gold NPs embedded in polyelectrolyte films composed of poly-L-lysine and poly-S-styrene were used to establish the relative Importance of both distance and electronic coupling Layer-by-layer construction of PE-NP films allowed for the position and density of NPs to be varied within the film to assess electronic coupling between particles (interparticle coupling) as well as at the electrode-film interface The cumulative results observed at these films suggest that while distance dependence prevails in nearly every case and interparticle coupling can contribute to facilitating the Fe(CN)(6)(3-/4-) electrochemistry interfacial electronic coupling of the PE-NP films is of critical Importance and decoupling is easily achieved by disengaging NP-electrode interactions (c) 2010 Elsevier B V All rights reserved