Nanostructured pencil graphite electrodes for application as high power biocathodes in miniaturized biofuel cells and bio-batteries

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.

Functionalization of MWCNTs for Bioelectrocatalysis by Bacterial Two-Domain Laccase from Catenuloplanes japonicus

“…They were modified with MWCNTs and Ac-875 laccase as described in Sections 2.7 and 2.8. The pencil rod-based electrode attracts significant attention for various bioelectrochemical applications due to their high availability, low cost, simplicity of use, mechanical strength, chemical inertness, functioning in a wide potential range effective adsorption of electroactive substances, easiness of surface modification, low toxicity, and simple disposal procedure [72][73][74]. It should be noted that the surface of graphite pencil rod electrodes is renewable, it does not require strict polishing procedures, and it provides good reproducibility of the results [75].…”

A novel, extreme low-cost poly (Erythrosine) modified pencil graphite electrode for determination of Adrenaline

“…GPE has gotten a lot of attention as a form of carbon electrode. GPEs has been employed in an expanding array of applications, primarily as sensors and biosensors, since the modern era, despite the fact that they were initially published in 1960 1 , 2 . It has good properties that are equivalent to glassy carbon and carbon paste electrode.…”