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Electrografted Interfaces on Metal Oxide Electrodes for Enzyme Immobilization and Bioelectrocatalysis
Author(s) -
Harris Tomos G. A. A.,
Heidary Nina,
Frielingsdorf Stefan,
Rauwerdink Sander,
Tahraoui Abbes,
Lenz Oliver,
Zebger Ingo,
Fischer Anna
Publication year - 2021
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.202100020
Subject(s) - electron transfer , immobilized enzyme , covalent bond , chemistry , oxide , indium tin oxide , electrode , biosensor , chemical engineering , materials science , combinatorial chemistry , photochemistry , nanotechnology , organic chemistry , enzyme , engineering
In this work, we demonstrate that diazonium electrografting of biocompatible interfaces on transparent conducting oxide indium tin oxide (ITO) can be controlled and optimized to achieve low charge transfer resistance, allowing highly efficient electron transfer to an immobilized model enzyme, the oxygen‐tolerant [NiFe]‐hydrogenase from Ralstonia eutropha . The use of a radical scavenger enables control of the interface thickness, and thus facilitates maximization of direct electron transfer processes between the enzyme's active center and the electrode. Using this approach, amine and carboxylic acid functionalities were grafted on ITO, allowing enzyme immobilization both under moderate electrostatic control and covalently via amide bond formation. Despite an initial decrease in catalytic activity, covalent immobilization led to an improvement in current stability compared to just electrostatically immobilized enzyme. Given the superior stability of electrografted interfaces in comparison to adsorbed or self‐assembled interfaces, we propose electrografting as an alternative approach for the functional immobilization of redox‐active enzymes on transparent conducting oxide (TCO) electrodes in bioelectronic devices.