Nanostructured materials based on the integration of ferrocenyl-tethered dendrimer andredox proteins on self-assembled monolayers: an efficient biosensor interface

Abstract

In this paper we report the use of ferrocenyl-tethered dendrimer (Fc-D) as anelectrode modifier supported by a self-assembled monolayer coated gold surface.The pretreatment of electrodes with Fc-D allows the covalent immobilization ofglucose oxidase. The resulting integrated hybrid system provides electrical contactbetween the redox center of the enzyme and the electrode, and improves the overallbioelectrocatalyzed oxidation of glucose. Cyclic voltammetry combined with surfaceplasmon resonance (SPR) is used to investigate the redox-induced orientationchanges of ferrocene-tethered dendrimers and the optimal electrical wiring of theenzyme, depending on the length of the alkyl chain of the ferrocene-tetheredgroups. The amount of substrate controls the steady-state concentration ratio ofFc/Fc+ in the film composition. Therefore, the SPR spectrum of the film is controlled by thereversible change in the refractive index of the enzyme-integrated redox film. The proposedmethod demonstrates a new procedure for developing a stable amperometric redoxenzyme-based sensor by designing a new nanostructured material that control thebiosensing performance.