title: Scalable, high performance, enzymatic cathodes based on nanoimprint lithography.
abstract: Here we detail high performance, enzymatic electrodes for oxygen bio-electroreduction, which can be easily and reproducibly fabricated with industry-scale throughput. Planar and nanostructured electrodes were built on biocompatible, flexible polymer sheets, while nanoimprint lithography was used for electrode nanostructuring. To the best of our knowledge, this is one of the first reports concerning the usage of nanoimprint lithography for amperometric bioelectronic devices. The enzyme (Myrothecium verrucaria bilirubin oxidase) was immobilised on planar (control) and artificially nanostructured, gold electrodes by direct physical adsorption. The detailed electrochemical investigation of bioelectrodes was performed and the following parameters were obtained: open circuit voltage of approximately 0.75 V, and maximum bio-electrocatalytic current densities of 18 µA/cm(2) and 58 µA/cm(2) in air-saturated buffers versus 48 µA/cm(2) and 186 µA/cm(2) in oxygen-saturated buffers for planar and nanostructured electrodes, respectively. The half-deactivation times of planar and nanostructured biocathodes were measured to be 2 h and 14 h, respectively. The comparison of standard heterogeneous and bio-electrocatalytic rate constants showed that the improved bio-electrocatalytic performance of the nanostructured biocathodes compared to planar biodevices is due to the increased surface area of the nanostructured electrodes, whereas their improved operational stability is attributed to stabilisation of the enzyme inside nanocavities.
authors.affiliation: Biomedical Sciences, Health and Society, Malmö University, 20560 Malmö, Sweden ; A.N. Bach Institute of Biochemistry, 119071 Moscow, Russia.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Pankratov
authors.affiliation: Division of Solid State Physics and The Nanometer Structure Consortium (nmC@LU), Lund University, 22100 Lund, Sweden.
authors.forename: Richard
authors.initials: R
authors.lastname: Sundberg
authors.affiliation: Biomedical Sciences, Health and Society, Malmö University, 20560 Malmö, Sweden.
authors.forename: Javier
authors.initials: J
authors.lastname: Sotres
authors.affiliation: Division of Solid State Physics and The Nanometer Structure Consortium (nmC@LU), Lund University, 22100 Lund, Sweden ; Neuronano Research Center, Medical Faculty, Lund University, 221 00 Lund, Sweden.
authors.forename: Dmitry B
authors.initials: DB
authors.lastname: Suyatin
authors.affiliation: Division of Solid State Physics and The Nanometer Structure Consortium (nmC@LU), Lund University, 22100 Lund, Sweden.
authors.forename: Ivan
authors.initials: I
authors.lastname: Maximov
authors.affiliation: Biomedical Sciences, Health and Society, Malmö University, 20560 Malmö, Sweden ; A.N. Bach Institute of Biochemistry, 119071 Moscow, Russia ; Kurchatov NBICS Centre, National Research Centre "Kurchatov Institute", 123182 Moscow, Russia.
authors.forename: Sergey
authors.initials: S
authors.lastname: Shleev
authors.affiliation: Division of Solid State Physics and The Nanometer Structure Consortium (nmC@LU), Lund University, 22100 Lund, Sweden ; Neuronano Research Center, Medical Faculty, Lund University, 221 00 Lund, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Montelius
keywords: bilirubin oxidase; bio-electrocatalysis; direct electron transfer; nanoimprint lithography; oxygen reduction reaction