Abstract
This work describes a simple method for the fabrication of an enzymatic electrode with high sensitivity to oxygen and good performance when applied as biocathode. Pencil graphite electrodes (PGE) were chosen as disposable transducers given their availability and good electrochemical response. After electrochemical characterization regarding hardness and surface pre-treatment suited modification with carbon-based nanostructures, namely with reduced graphene, MWCNT and carbon black for optimal performance was proceeded. The bioelectrode was finally assembled through immobilization of bilirubin oxidase (BOx) lashed on the modified surface of MWCNT via π–π stacking and amide bond functionalization. The high sensitivity towards dissolved oxygen of 648 ± 51 µA mM−1 cm−2, and a LOD of 1.7 µM, was achieved for the PGE with surface previously modified with reduced graphene (rGO), almost the double registered for direct anchorage on the bare PGE surface. Polarization curves resulted in an open circuit potential (OCP) of 1.68 V (vs Zn electrode) and generated a maximum current density of about 650 μA cm−2 in O2 saturated solution.
Highlights
This work describes a simple method for the fabrication of an enzymatic electrode with high sensitivity to oxygen and good performance when applied as biocathode
The immobilization procedure consisted of tethering bilirubin oxidase (BOx) enzyme to multi-walled carbon nanotubes (MWCNTs) by pyrene-based succinimidyl ester compound (PBSE), as performed by Ramasamy et al.[12]
Pencil graphite electrodes (PGE) HBs had better kinetics since peak-to-peak separation was lower (∆Ep = 0.09 V) in agreement with the results reported by K ariuki[18]
Summary
This work describes a simple method for the fabrication of an enzymatic electrode with high sensitivity to oxygen and good performance when applied as biocathode. First reported in 1 9602, PGEs have been used in an increasing number of applications, and as sensors and biosensors since the new m illennium[3,4,5,6] In some studies their use was justified by achievement of similar if not better analytical performance over glassy carbon (GCE) and highly ordered pyrolytic graphite electrodes while others gave notice of poor kinetics c haracteristics[6]. The high electrocatalytic performance achieved with the proposed PGE indicates favorable and oriented bilirubin oxidase immobilization on the surface of nanotubes It allows foreseeing the possibility of being able of use as biocathode in miniaturized energy sources
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
