Fabrication of a Nanobiocomposite Film Containing Heme Proteins and Carbon Nanotubes on a Choline Modified Glassy Carbon Electrode: Direct Electrochemistry and Electrochemical Catalysis

Abstract

A nanocomposite electrochemical sensing film is assembled on choline (Ch) modified glassy carbon electrode (GCE), which contains multiwalled carbon nanotubes (MWNTs), Nafion cation exchanger, and myoglobin (Mb) or hemoglobin (Hb). The MWNTs provide a 3D porous and conductive network for the enzyme immobilization and Nafion acts as polymeric binder to give cast thin films. Both MWNTs and Nafion provide negative functionalities to bind to the positively charged redox proteins and to attach at the positively charged Ch modified layer, and drive the formation of homogeneous and stable nanocomposite film, the MWNT-Nafion-Mb. The nanocomposite film was characterized by field emission scanning electron microscope (FE-SEM). The Mb in the nanocomposite film showed a pair of well-defined and nearly reversible cyclic voltammetric peaks at about À 0.32 V vs. SCE at pH 7.0 solution for the heme Fe(III)/Fe(II) redox couple. The immobilized heme proteins can display the features of peroxidase in electrocatalytic reductions of oxygen, hydrogen peroxide, nitric oxide, trichloroacetic acid (TCA), and bromate.

Carbon Nanotubes as Suitable Electrochemical Platforms for Metalloprotein Sensors and Genosensors

“…Figure 5 comparatively shows the remarkable changes in the electrochemical response of myoglobin in absence or in presence of oxygen. In aerobic conditions the electrocatalytic effect is reflected in an increase of the Fe(III) reduction peak accompanied by the disappearance of Fe(II) oxidation peak (Zhang, 2004;Zhao, 2006;Zhao, 2006 a;Zhang, 2007;Li, 2006). Such catalytic effect can be explained by the following path.…”

“…The detection of H 2 O 2 has been carried out at such low overpotentials that interferences with other analytes can be minimized (Wang, 2003;Rubianes, 2006). Direct electron transfer has also been obs e r v e d w i t h m a n y m e t a l l o p r o t e i n s s u c h a s cytochrome C, horseradish peroxidase, microperoxidase (MP-11), myoglobin, hemoglobin, catalase, azurin, etc, immobilized on different CNT modified electrodes (Gooding, 2003;Yu, 2003;Zhao, 2006;Zhao, 2006a;Zhang, 2007;Li, 2006;Zhang, 2004;Esplandiu, 2009a;Pacios, 2009. Palangsuntikul, 2010Kumar, 2011).…”

“…Myoglobin (Mb), a small water soluble protein involved in the binding and storage of oxygen in cells, has been the subject of numerous studies in redox protein sensors. This protein has a hemin core capable of redox activity and exhibits a catalytical response in presence of some analytes such as oxygen, H 2 O 2 or NO (Zhang, 2004;Li, 2006;Zhao, 2006;Pacios, 2009;Esplandiu, 2009a). It is generally difficult for Mb to transfer electrons to a conventional electrode, but CNT electrodes have once again demonstrated their performance as suitable electrode material for such protein and have promoted applications as potential (bio)sensors of oxygen or hydrogen peroxide or as reduction catalyst in batteries and fuel cell systems.…”

“…It is generally difficult for Mb to transfer electrons to a conventional electrode, but CNT electrodes have once again demonstrated their performance as suitable electrode material for such protein and have promoted applications as potential (bio)sensors of oxygen or hydrogen peroxide or as reduction catalyst in batteries and fuel cell systems. Taking advantage of the CNT benefits as electrode substrates for (bio)sensing, some groups have investigated the physisorbed Mb response on randomly dispersed carbon nanotube modified substrates (Zhang, 2004;Li, 2006;Zhao, 2006). In all cases, direct electron exchange between Mb and CNT was observed in a quasi-reversible heme Fe(III)/Fe(II) voltammetry response.…”

The Investigation of Electrochemistry Behaviors of Tyrosinase Based on Directly Electrodeposited Graphene on Choline–Gold Nanoparticals

“…The quaternary ammonium -N + (CH3)3 functional groups 4 of the choline modified layer were with positive charge, which may interact with the negatively charged nanobiocomposite film such as AuNPs [46]. The choline layer could not only fix Au colloids but also promote the direct electron transfer of proteins [45].…”