title: Nanoparticle film assemblies as platforms for electrochemical biosensing--factors affecting the amperometric signal enhancement of hydrogen peroxide.
abstract: Factors affecting the enhanced amperometric signal observed at electrodes modified with polyelectrolyte-gold nanoparticle (Au-NP) composite films, which are potential interfaces for first-generation biosensors, were systematically investigated and optimized for hydrogen peroxide (H2O2) detection. Polyelectrolyte multilayer films embedded with citrate-stabilized gold nanoparticles exhibited high sensitivity toward the oxidation of H2O2. From this Au-NP film assembly, the importance of Au-NP ligand protection, film permeability, the density of Au-NPs within the film, and electronic coupling between Au-NPs (interparticle) and between the film and the electrode (interfacial) were evaluated. Using alternative Au-NPs, including those stabilized with thiols, polymers, and bulky ligands, suggests that the amperometric enhancement of H2O2 is optimized at poly-L-lysine-linked film assemblies embedded with Au-NPs possessing small, charged, and conductive (conjugated) peripheral ligands. As a potential application of these Au-NP film assemblies, an enhanced amperometric signal for H2O2 oxidation was shown for modified "needle" electrodes. The overall aim of this research is to gain a greater understanding of designing electrochemical sensing strategies that incorporate Au-NPs and target specific analytes.
authors.affiliation: Department of Chemistry, Gottwald Center for the Sciences, University of Richmond, Richmond, Virginia 23173, USA.
authors.forename: Adrienne R
authors.initials: AR
authors.lastname: Schmidt
authors.forename: Natalie D T
authors.initials: ND
authors.lastname: Nguyen
authors.forename: Michael C
authors.initials: MC
authors.lastname: Leopold
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D019343:Citric Acid / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction
chemical_list: D019343:Citric Acid; D006046:Gold; D006861:Hydrogen Peroxide