Direct Electron Transfer of Hemoglobin and Myoglobin at the Bare Glassy Carbon Electrode in an Aqueous BMI.BF₄ Ionic‐Liquid Mixture

Abstract

Direct and remarkably fast electron transfers between a bare glassy carbon electrode and heme proteins (hemoglobin or myoglobin) are obtained by using an aqueous 1-butyl-3-methyl imidazolium tetrafluoroborate (BMI.BF(4)) ionic-liquid mixture as electrolyte. The ionic liquid is observed to play a key role in the achievement of the electron transfer. The experimental data show that the proteins are not strongly adsorbed onto the electrode surface while giving rise to sharp and well-defined redox responses. Such a finding contrasts with most of the reported works found in literature and-beyond the fundamental aspect--it may be of interest in applications where adsorption is critical. Moreover, the electrocatalytic activity of the proteins toward the reduction of oxygen and nitrite in the aqueous BMI.BF(4) mixture is evidenced, showing the potential of this simple approach for bioelectroanalytical devices.

Electrochemical Determination and Antioxidant Capacity Modulation of Polyphenols in Deep Eutectic Solvents

“…Electrochemical Measurements. The measurements were performed either with carbon screen-printed electrodes (carbon SPE, DRP 110-Dropsens) purchased from Metrohm or with a homemade three-electrode cell 30 using a glassy carbon working electrode (disk of 1 mm diameter), a platinum wire as a counter electrode, and a silver wire as a quasi-reference. A drop of 50 μL of solution of phenolics in DES-based media was used with SPE, allowing to cover the three-electrode system, while 200 μL of solution was employed with the homemade cell.…”

An optimal surface concentration of pure cardiolipin deposited onto glassy carbon electrode promoting the direct electron transfer of cytochrome-c

“…[24] The estimated kinetic rate constant also falls in the range reported for other redox proteins in solution. [53] This result shows that only a small amount of pure cardiolipin (7 μg cm -2 ) simply deposited by solvent evaporation is sufficient for promoting the direct electron transfer of cytochrome-c in solution as a stable and reproducible redox signal at a modified glassy carbon electrode.…”

Ionic liquids designed for advanced applications in bioelectrochemistry

“…The redox reaction has been studied of protein dissolved in a mixture of IL and water using an electrochemical method, thin layer cyclic voltammetry. 63 Direct and rapid redox reaction of Hb or Mb was observed in an aqueous solution containing 1 M [C4mim]BF 4 . The IL was observed to play a key role in the electron transfer.…”