Freestanding biopellet electrodes based on carbon nanotubes and protein compression for direct and mediated bioelectrocatalysis

The fabrication of bioelectrocatalytic protein electrodes by the simple compression of carbon nanotube and protein powders was investigated using a series of proteins including bilirubin oxidase (BOx), bovine serum albumin (BSA), catalase, cytochrome C (Cyt C), diaphorase, FAD-dependent glucose dehydrogenase (FAD-GDH), galactose oxidase (GAOx), glucose oxidase (GOx), horseradish peroxidase (HRP), laccase and urease. The isoelectric points (pI) of the proteins ranged from 3.5 to 12 and the molecular weights ranged from 12.4 to 480 kDa. The compression of diaphorase, laccase, BOx, FAD-GDH, catalase and urease gave mechanically stable biopellets in 0.1 M phosphate buffer pH 7.4. For Cyt C, BSA, GAOx, GOx, and HRP, contact with buffer destabilised the biopellet and induced a fast destruction of the composite. In parallel, stable redox pellets were obtained with differently charged redox mediators: hexaammineruthenium (III) chloride, potassium hexacyanoferrate or 1,4-naphthoquinone. Several parameters were explored to shed new light on the factors that determine biopellet stability. Stable biopellets capable of direct and mediated electron transfer were subsequently elaborated, for O2 reduction and glucose oxidation, respectively, based on the simplified procedure that does not require stabilising protection membranes or holders on the contrary to existing methods.

Références

Titre
Freestanding biopellet electrodes based on carbon nanotubes and protein compression for direct and mediated bioelectrocatalysis
Type de publication
Article de revue
Année de publication
2021
Revue
Electrochemistry Communications
Volume
122
Start Page
106895
ISSN
13882481
Soumis le 18 décembre 2020