title: Fabrication of enzyme-based coatings on intact multi-walled carbon nanotubes as highly effective electrodes in biofuel cells.
abstract: CNTs need to be dispersed in aqueous solution for their successful use, and most methods to disperse CNTs rely on tedious and time-consuming acid-based oxidation. Here, we report the simple dispersion of intact multi-walled carbon nanotubes (CNTs) by adding them directly into an aqueous solution of glucose oxidase (GOx), resulting in simultaneous CNT dispersion and facile enzyme immobilization through sequential enzyme adsorption, precipitation, and crosslinking (EAPC). The EAPC achieved high enzyme loading and stability because of crosslinked enzyme coatings on intact CNTs, while obviating the chemical pretreatment that can seriously damage the electron conductivity of CNTs. EAPC-driven GOx activity was 4.5- and 11-times higher than those of covalently-attached GOx (CA) on acid-treated CNTs and simply-adsorbed GOx (ADS) on intact CNTs, respectively. EAPC showed no decrease of GOx activity for 270 days. EAPC was employed to prepare the enzyme anodes for biofuel cells, and the EAPC anode produced 7.5-times higher power output than the CA anode. Even with a higher amount of bound non-conductive enzymes, the EAPC anode showed 1.7-fold higher electron transfer rate than the CA anode. The EAPC on intact CNTs can improve enzyme loading and stability with key routes of improved electron transfer in various biosensing and bioelectronics devices.
authors.affiliation: Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.|Department of Energy and Environmental Engineering, Korea University of Science and Technology (UST), Seoul 02792, Republic of Korea.
authors.forename: Byoung Chan
authors.initials: BC
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Inseon
authors.initials: I
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Seok-Joon
authors.initials: SJ
authors.lastname: Kwon
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Youngho
authors.initials: Y
authors.lastname: Wee
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Ki Young
authors.initials: KY
authors.lastname: Kwon
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Chulmin
authors.initials: C
authors.lastname: Jeon
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Hyo Jin
authors.initials: HJ
authors.lastname: An
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea.
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung
authors.affiliation: The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-2710, USA.
authors.forename: Su
authors.initials: S
authors.lastname: Ha
authors.affiliation: Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Dordick
authors.affiliation: Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea.|Green School, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Jungbae
authors.initials: J
authors.lastname: Kim