Electrochemical Studies Based on Local Interfacial pH Changes of Gold Nanoparticles Immobilized on Polystyrene Brushes

• Published in: International journal of electrochemical science 2013-03, Vol.8 (3), p.4150-4159
• Main Authors: Antonio, Tamara R.T.A., Basso, Caroline R., Cabral, Murilo F., Pedrosa, Valber A.
• Format: Article
• Language: English
• Subjects: gold nanoparticle; Local pH change; Polymer brushes; stimuli-responsive materials
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)14461-0

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.