Direct electrochemistry and electrocatalysis of myoglobin using an ionic liquid-modified carbon paste electrode coated with Co3O4 nanorods and gold nanoparticles

Construction of myoglobin–amphiphilic alginate caprylamide–graphene composite modified electrode for the direct electron transfer between redox proteins and electrode and electrocatalysis of myoglobin

“…However, their positions and shapes were similar to that of Mb. As the shapes and positions of the amide I and II infrared absorbance peaks of Mb can provide detailed information on the secondary structure of the polypeptide chain, 6 the above results indicated that Mb could retain its native structure in Mb–ACA–GR composite during the fabrication of the modified electrode.…”

“…Myoglobin (Mb) is one of the ideal redox proteins because of its known structure, commercial availability, and relatively low molecular weight, and its direct electron transfer is attributed to the bioactive heme Fe( iii )/Fe( ii ) redox couple. 6 However, the direct electron transfer between the redox protein and the surface of bare electrodes is often difficult to achieve, which is attributed to the deeply embedded redox active center in the structure of proteins, the unfavorable orientation of protein molecules and the irreversible adsorption of denatured proteins on the electrode surface. 7–9 For these reasons, many materials such as polymers, metal oxide nanoparticles, and graphene 10–12 have been applied to modify the substrate electrode.…”

A novel biosensor based on electro-co-deposition of sodium alginate-Fe3O4-graphene composite on the carbon ionic liquid electrode for the direct electrochemistry and electrocatalysis of myoglobin

“…The peaks at 1654.36 and 1542.46 cm -1 , respectively, corresponded to amide I and II infrared absorbance peaks of Mb, whose position and shape were similar with that of Mb-SA-Fe 3 O 4 -GR composite film (1654.03 and 1539.19 cm -1 ). As the shape and position of the amide I and II infrared absorbance peaks of Mb can provide detailed information on the secondary structure of the polypeptide chain [34], the above results suggested that Mb could keep its native structure after being immobilized in the SA-Fe 3 O 4 -GR composite film. UV-Vis adsorption spectrum is another way to test the structure change of Mb.…”

“…The synergistic effects of SA and Fe 3 O 4 -GR composite incorporated in the film accelerated the electron transfer rate, making Nafion/Mb-SA-Fe 3 O 4 -GR/CILE present biggest redox peak currents among the modified electrodes. From cyclic voltammogram of Nafion/Mb-SA-Fe 3 O 4 -GR/CILE, the redox peak potentials were recorded with the cathodic peak potential (Epc) as -0.302 V and the anodic peak potential (E pa ) as -0.224 V. The formal peak potential (E 0 0 ) was calculated as -0.263 V (vs. SCE), which was the typical value of the active center of Mb Fe(III)/ Fe(II) redox couple [34]. Therefore, the direct electron transfer of Mb was attributed to the heme Fe(III)/Fe(II) redox couple in the Mb molecules and it could be realized on the Nafion/Mb-SA-Fe 3 O 4 -GR/CILE with fast electron transfer rate.…”

“…Carbon ionic liquid electrode (CILE), prepared by simply incorporating the binder and the modifier of ionic liquid into the carbon past electrode, possesses the specific advantages, such as excellent conductivity, high sensitivity, wide electrochemical windows and good anti-fouling ability, which has been proved to be an effective working electrode in the field of electrochemical sensor [33,34]. In general, electro-co-deposition is performed on the metal electrode, such as the bulk gold electrode, while few work of CILE as the substrate electrode applied in the electro-co-deposition process was reported.…”