Direct Electron Transfer of Cellobiose Dehydrogenase on Positively Charged Polyethyleneimine Gold Nanoparticles

Abstract

What prompted you to investigate this topic/problem? Cellobiose dehydrogenase (CDH) is one of the few sugar oxidising enzymes that shows efficient direct electron transfer (DET) characteristics with electrodes and thus av ery good candidate for making third-generation biosensors and bioanodes for biofuel cells. However,DET relies on good communication between the cy-tochrome domain (CYT) and the electrode. On an aked electrode CDH is expected to adsorb randomly meaning that all CYTsw ill not make efficient contact with the electrode. In this study,w e combined two approaches to ensure advantageous orientation of as many CDH molecules as possible through:1)making the electrode surface positively charged using polyethyleneimine and 2) nanostructuring the electrode surface with gold nanoparticles. This combination increased both the percentage of better orientated CDH molecules and current density leading to the sensitive detection of lactose. Who contributed to the idea behind the cover? Mojtaba Ta vahodi, Christopher Schulz and Roland Ludwig joined forces to come up with the ideas that were expressed graphically on the cover picture. M.T.p repared the final version of the cover. What are the main challengesi nthe broad area of your research? The main challenges are to design an electrode surface onto which ah igh surface concentration of biomolecule(s) can be immobilised and at the same time be orientated so that DET will be facilitated between the redox active sites of the biomolecule and the electrode. This guarantees long-term integrity of the biomolecule and also allows other molecules, such as substrates and products, to have access to the reaction centres of the biomolecule. Who pays the bill for the research highlighted on the cover?

Trimethylamine N‐Oxide Electrochemical Biosensor with a Chimeric Enzyme

“…Remarkably, the maximum response for TMAO is already reached at very low amount of TorA‐FDH (7,07 pmol/cm 2 ) (Figure ). Due to the higher enzymatic activity of TorA‐FDH, its maximum response is reached at much lower loading compared to other described enzyme electrodes where an enzyme is adsorbed on an electrode surfaces ,. However, a tenfold reduction of the applied amount resulted in a clear drop of response.…”

Fuel-independent and membrane-less self-charging biosupercapacitor

“…Asprepared NP 9 were electrostatically coated with polycations polyethyleneimine (NP (+) ) or poly(allylamine hydrochloride) with a subsequent coverage with polyanion poly(sodium 4styrenesulfonate) (NP (-) ) to obtain a positively or a negatively charged surface in neutral media following previously reported protocols. 15 Detailed description of the experimental procedures is provided in the Supporting Information. Mb was immobilised on glassy carbon electrodes modified with NP (-) or NP (+) to create diverse surface charges for suitable protein orientation.…”

A Third Generation Glucose Biosensor Based on Cellobiose Dehydrogenase Immobilized on a Glassy Carbon Electrode Decorated with Electrodeposited Gold Nanoparticles: Characterization and Application in Human Saliva

“…The first domain, called dehydrogenase domain (DH CDH ), contains a flavin adenine dinucleotide (FAD) cofactor, connected through a flexible linker to a second subunit containing a heme-b cofactor, called cytochrome domain (CYT CDH ) [ 30 ]. DH CDH domain is structurally similar to the FAD domain of most GMC-oxidoreductase enzymes and is fully reduced by di-/mono- saccharides, transferring the electrons through internal electron transfer (IET) to the CYT CDH , which finally shuttles the electrons to properly modified electrodes [ 31 ]. Among II class CDHs, Corynascus thermophilus CDH ( Ct CDH) was genetically mutated in its active site ( Ct CDH C291Y mutant) to enhance its sensitivity toward glucose and reduce the maltose cross-reactivity [ 32 ].…”