Electrochemical Behavior of Cytochrome C Immobilized in a Magnetically Induced Mesoporous Framework

Abstract

Protein immobilization on electrode surfaces remains a technological challenge and is decisive in enhancing biological properties with simplified operational steps. In view of proposing a new direction for protein immobilization, we report the development of a mesoporous framework resulting from the magnetically induced assembly of magnetite nanoparticles decorated with near‐monodisperse gold nanoparticles onto an indium‐tin‐oxide electrode. With an electrochemically active surface area of about 72 cm2 and pores with an average size of 31±1 nm, this magnetically induced mesoporous framework is suitable for the immobilization of small redox proteins. As a proof‐of‐concept, we show the electrochemical process of cytochrome c, where the mesoporous electrode provided a fourfold enhancement for the faradaic currents in comparison to standard polycrystalline gold electrodes.

Magnetically Stimulated Bio‐ and Electrochemical Systems: State‐of‐the‐Art, Applications, and Future Directions

“…Engineered bifunctional nanoparticles also enabled the magnetically-induced assembly of a mesoporous framework on indium-thin oxide electrodes, resulting in the enhanced redox reaction of cytochrome c (Cyt c). [184] In this case, magnetite nanoparticles were decorated with gold nanoparticles, and magnetically attracted to the surface of the electrode, leading to a porous framework with mesopores of 31 � 1 nm and an electrochemically active surface area (ECSA) of 72 cm 2 . As shown in Figure 14, the subsequent immobilization of Cyt c on the gold domains of the mesoporous electrode was marked by a 10-fold enhancement for the enzyme's oxidation processes in comparison to Cyt c modified polycrystalline gold electrode with an ECSA of 6.25 cm 2 .…”

“…As shown in Figure 14, the subsequent immobilization of Cyt c on the gold domains of the mesoporous electrode was marked by a 10-fold enhancement for the enzyme's oxidation processes in comparison to Cyt c modified polycrystalline gold electrode with an ECSA of 6.25 cm 2 . [184] The combination of bifunctional nanoparticles with superparamagnetic Fe 3 O 4 /graphene oxide nanosheets was recently Figure 13. (a) Illustrative scheme of a microbial bio-fuel cell (MBFC).…”

“…This strategy allowed detecting an alzheimer's disease biomarker from plasma samples with a limit of detection of 66 nM by monitoring the water oxidation reaction. Engineered bifunctional nanoparticles also enabled the magnetically‐induced assembly of a mesoporous framework on indium‐thin oxide electrodes, resulting in the enhanced redox reaction of cytochrome c (Cyt c) [184] . In this case, magnetite nanoparticles were decorated with gold nanoparticles, and magnetically attracted to the surface of the electrode, leading to a porous framework with mesopores of 31±1 nm and an electrochemically active surface area (ECSA) of 72 cm 2 .…”

“…Electrolyte support: 5 mmol.L −1 phosphate buffer solution, pH 7.0 at 25 °C. Adapted with permission [184] . Copyright 2019, Wiley.…”

Challenges in Biomaterials Science for Electrochemical Biosensing and Bioenergy

“…In addition, such materials can provide a favorable enzyme orientation for achieving the enzyme DET. Metal and metal oxide nanoparticles, as well as nanostructured carbon-based materials, such as carbon nanotubes and carbon nanoparticles, have been extensively used for this purpose, − contributing to achieving remarkable current densities of several mA cm –2 . − …”