Schmidt AR, Nguyen NDT, Leopold MC. Nanoparticle film assemblies as platforms for electrochemical biosensing--factors affecting the amperometric signal enhancement of hydrogen peroxide.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013;
29:4574-83. [PMID:
23473024 DOI:
10.1021/la400359x]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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.
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