Electrochemical characterization of graphene and MWCNT screen-printed electrodes modified with AuNPs for laccase biosensor development

摘要

The aim of this work is to show how the integration of gold nanoparticlesud(AuNPs) into multi-wall-carbon-nanotubes (MWCNTs) based screen-printed electrodesudand into graphene-based screen-printed electrodes (GPHs) could represent a potential wayudto further enhance the electrochemical properties of those electrodes based onudnanoparticles. Laccase from Trametes versicolor (TvL) was immobilized over MWCNTsudand GPH previously modified with AuNPs (of 5 and 10 nm). The characterization of theudmodified electrode surface has been carried out by cyclic voltammetry. The results showedudthat the use of AuNPs for modification of both graphene and MWCNTs screen-printedudelectrode surfaces would increase the electrochemical performances of the electrodes.udMWCNTs showed better results than GPH in terms of higher electroactive area formationudafter modification with AuNPs. The two modified nanostructured electrodes wereudsuccessively proven to efficiently immobilize the TvL; the electrochemical sensingudproperties of the GPH- and MWCNT-based AuNPs-TvL biosensors were investigated byudchoosing 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic-acid diammonium salt (ABTS),udcatechol and caffeic acid as laccase mediators; and the kinetic parameters of the laccaseudbiosensor were carefully evaluated.