Adsorption and Direct Electron Transfer from Hemoglobin into a Three-Dimensionally Ordered Macroporous Gold Film

Abstract

Application of protein‐based, direct electron communication in bioelectronic devices, biosensors, or biofuel cells usually requires high stability and function density of the immobilized proteins or enzymes. Traditional methods have been used to increase the function density using multilayer immobilization techniques at the expense of losing stability and electron‐communication rate, that is, generally only protein molecules near the electrode surface are electroactive. In order to overcome the above problems, a three‐dimensional, ordered, macroporous gold film electrode is synthesized electrochemically by an inverted colloidal crystal template technique. The uniform, three‐dimensional macroporous gold provides superior conductivity, high stability, and large surface area. Its interconnected macroporous structure, containing gold nanoparticles, significantly enhances the amount of adsorbed hemoglobin (Hb) molecules at the monolayer level and also provides a good microenvironment for retaining the biological activity of the adsorbed protein, as confirmed by electrochemical and attenuated total reflection Fourier‐transform infrared spectroscopy. Therefore, direct electron transfer between the adsorbed Hb and the electrode is achieved. Adsorption of Hb on the macroporous gold film electrode is monitored using electrochemical impedance spectroscopy. The saturated adsorption amount, Γ, of the Hb is determined to be 6.55×10–10 mol cm–2 with a surface coverage of 88.1 %. The electrochemical behavior and the adsorption mechanism of Hb on the macroporous gold film electrode are discussed on the basis of the experimental results.

Comparative electrochemistry of haemoglobin on the long and ball milling shortened carbon nanotubes

“…It is well known that proteins containing heme groups are capable of reducing hydrogen peroxide (H 2 O 2 ) [33]. Hence we studied the electrocatalytic behaviour of haemoglobin towards H 2 O 2 on the two kinds of modified electrodes.…”

Electroactive Film of Myoglobin Incorporated in a 3D-porous Calcium Alginate Film with Polyvinyl Alcohol, Glycerin and Gelatin

“…[1][2][3] In recent years, direct electron transfer (DET) between enzymes and electrodes has been achieved by incorporating some kinds of enzymes into an appropriate thin film modified on the electrode surface. 4,5 Such a thin film may provide a favorable microenvironment for the proteins, and enhance the DET between proteins and electrodes, thus offering opportunities for investigating the enzyme electrochemistry. 3,6 Successful examples have included cast films of proteins with biopolymers, 7 insoluble surfactants, 8 hydrogel polymers, 9 and inorganic-organic composite materials.…”

Facile Interfacial Electron Transfer of Hemoglobin

“…This has motivated great interest in design new protein films that are suitable for direct protein electrochemistry. For example, Xia and coworkers reported the direct chemistry of Hb on a three-dimentionally ordered macropourous gold film [17]. More importantly, efforts have been taken to develop novel biosensors and bioelectronic devices based on this research.…”