title: Carboxylated or aminated polyaniline-multiwalled carbon nanotubes nanohybrids for immobilization of cellobiose dehydrogenase on gold electrodes.
abstract: Polymer-multiwalled carbon nanotube (MWCNT) nanohybrids, which differ in surface charge have been synthesized to study the bioelectrocatalysis of adsorbed cellobiose dehydrogenase (CDH) from Phanerochaete sordida on gold electrodes. To obtain negatively charged nanohybrids, poly(3-amino-4-methoxybenzoic acid-co-aniline) (P(AMB-A)) was covalently linked to the surface of MWCNTs while modification with p-phenylenediamine (PDA) converted the COOH-groups to positively charged amino groups. Fourier transform infrared spectroscopy (FTIR) measurements verified the p-phenylenediamine (PDA) modification of the polymer-CNT nanohybrids. The positively charged nanohybrid MWCNT-P(AMB-A)-PDA promoted direct electron transfer (DET) of CDH to the electrode and bioelectrocatalysis of lactose was observed. Amperometric measurements gave an electrochemical response with KMapp = 8.89 mM and a current density of 410 nA/cm(2) (15 mM lactose). The catalytic response was tested at pH 3.5 and 4.5. Interference by ascorbic acid was not observed. The study proves that DET between the MWCNT-P(AMB-A)-PDA nanohybrids and CDH is efficient and allows the sensorial detection of lactose.
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology (IZI-BB), Branch Bioanalytics and Bioprocesses Potsdam-Golm, Am Mühlenberg 13, 14476 Potsdam, Germany; E-Mail: fschell@uni-potsdam.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Tanne
authors.affiliation: Food Biotechnology Laboratory, Department of Food Sciences and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; E-Mails: daniel.kracher@boku.ac.at (D.K.); roland.ludwig@boku.ac.at (R.L.).
authors.forename: Daniel
authors.initials: D
authors.lastname: Kracher
authors.affiliation: Institute for Thin Film and Microsensoric Technology, Kantstr. 55, 14513 Teltow, Germany; E-Mails: b.dietzel@gmx.net (B.D.); buschu@uni-potsdam.de (B.S.).
authors.forename: Birgit
authors.initials: B
authors.lastname: Dietzel
authors.affiliation: Institute for Thin Film and Microsensoric Technology, Kantstr. 55, 14513 Teltow, Germany; E-Mails: b.dietzel@gmx.net (B.D.); buschu@uni-potsdam.de (B.S.).
authors.forename: Burkhard
authors.initials: B
authors.lastname: Schulz
authors.affiliation: Food Biotechnology Laboratory, Department of Food Sciences and Technology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria; E-Mails: daniel.kracher@boku.ac.at (D.K.); roland.ludwig@boku.ac.at (R.L.).
authors.forename: Roland
authors.initials: R
authors.lastname: Ludwig
authors.affiliation: Biosystems Technology, Institute of Applied Life Sciences, Technical University of Applied Sciences Wildau, Hochschulring 1, 15745 Wildau, Germany; E-Mail: flisdat@th-wildau.de.
authors.forename: Fred
authors.initials: F
authors.lastname: Lisdat
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology (IZI-BB), Branch Bioanalytics and Bioprocesses Potsdam-Golm, Am Mühlenberg 13, 14476 Potsdam, Germany; E-Mail: fschell@uni-potsdam.de.
authors.forename: Frieder W
authors.initials: FW
authors.lastname: Scheller
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology (IZI-BB), Branch Bioanalytics and Bioprocesses Potsdam-Golm, Am Mühlenberg 13, 14476 Potsdam, Germany; E-Mail: fschell@uni-potsdam.de.
authors.forename: Frank F
authors.initials: FF
authors.lastname: Bier
keywords: cellobiose dehydrogenase; multiwalled carbon nanotubes; nanohybrids; polyaniline