Diameter dependence of single-walled carbon nanotubes with flavin adenine dinucleotide glucose dehydrogenase for direct electron transfer bioanodes

Abstract

The diameter dependence of single-walled carbon nanotubes (SWCNTs) with flavin adenine dinucleotide glucose dehydrogenase (FAD-GDH) for direct electron transfer (DET) type bioanodes is presented for the first time. In order to address the issue, we use SWCNTs having different diameters fabricated by direct-injection pyrolytic synthesis, which can control the diameter in a wide range with the other parameters fixed. Three different diameters of SWCNTs are examined: average diameter d m = 1.0, 1.5, and 2.0 nm. In order to achieve DET, a debundled, individual SWCNT has to be placed at the FAD position in the GDH protein pocket. The bioanodes with d m = 1.0 and 1.5 nm SWCNTs show better performance than that with d m = 2.0 nm SWCNTs. The diameter dependence of SWCNTs for bioanode performance is thought to be related to the distance between the SWCNTs and FAD positioned in the reaction center of the GDH protein shell.

Aromaphilicity Index of Amino Acids: Molecular Dynamics Simulations of the Protein Binding Affinity for Carbon Nanomaterials

“…A previous work examining direct electron-transfer bioanodes using CNTs with flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) suggested that a CNT is inserted into the groove of FAD-GDH . In fact, the groove of FAD-GDH was found to show relatively high aromaphilicity (Supporting Information, Figure S4).…”

“…A previous work examining direct electron-transfer bioanodes using CNTs with flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) suggested that a CNT is inserted into the groove of FAD-GDH. 68 In fact, the groove of FAD-GDH was found to show relatively high aromaphilicity (Supporting Information, Figure S4). A future challenge using the aromaphilicity index is to control the protein binding affinity for aromatic carbon surfaces, including that of nanomaterials and solutes, by designing aromaphilicity profiles of protein surfaces using point mutations, which can contribute to a wide range of protein applications, such as bioimaging, biomedicine, biosensing, and drug delivery.…”

Effect of electrochemical functionalization of single-walled carbon nanotube electrodes in flexible enzymatic biofuel cells

“…17,18) Moreover, owing to their unique dimensions, SWNTs can closely approach the active centers of enzymes, thus possibly making direct electron transfer (DET) via the tunneling process more feasible. 19) Hence, SWNT thin films are optimal candidates for the DET electrodes of flexible EBFCs for realizing selfpowered wearable sensors.…”

“…The enzymes glucose oxidase (GOx) from Aspergillus niger (Tokyo Chemical Industry) and horseradish peroxidase (HRP) (Sigma-Aldrich) were used at the anode, while laccase from Trametes versicolor (Sigma-Aldrich) was used at the cathode. The enzymes facilitate highly specific catalysis and the electrons may be easily transferred to the SWNTs owing to their close contact with the active centers of the enzymes, 19) as illustrated in Fig. 1(b).…”