Electrochemical studies based on local interfacial ph changes of gold nanoparticles immobilized on polystyrene brushes

• Autor(a) principal: Antonio, Tamara R. T. A. [UNESP]
• Data de Publicação: 2013
• Outros Autores: Basso, Caroline R. [UNESP], Cabral, Murilo F., Pedrosa, Valber A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://www.electrochemsci.org/papers/vol8/80304150.pdf; http://hdl.handle.net/11449/112689
• topic: Polymer brushes; Local pH change; gold nanoparticle; stimuli-responsive materials

The electrochemical behavior of polystyrene modified with gold nanoparticle (Au NPs) was investigated in terms of pH-responsive polymer brush. A pH-responsive of modified polymer brush from tethered polystyrene was prepared and used for selective gating transport of anions and cations across the thin-film. An ITO-coated glass electrode was used as substrate and applied to study the switchable permeability of the polymer brush triggered by changes in pH of the aqueous environment. The pH-sensitive behavior of the polymer brush interface has been demonstrated by means of cyclic voltammetry (CV) and Localized Surface Plasmon Resonance (LSPR). CV experiments showed at ph values of 4 and 8 induces swelling and shrinking of the grafted polymer brushes, respectively, and this behavior is fast and reversible. LSPR measurements showed a blue shift of 33 nm in the surface resonance band changes by local pH. The paper brings an easy methodology to fabrication a variety of nanosensors based on the polymer brushes-nanoparticle assemblies.