Disposable electrodes modified with multi-wall carbon nanotubes for biosensor applications

This paper deals with the development of a disposable electrochemical sensor for the detection of hydrogen peroxide, using screen-printed carbon-based electrodes (SPCEs) modified with multi-wall carbon nanotubes (MWCNs) dispersed in a polyethylenimine (PEI) mixture. The modified sensors showed an excellent electrocatalytic activity towards the analyte, respect to the high overvoltage characterising unmodified screen-printed sensors. The composition of the PEI/MWCNT dispersion was optimised in order to improve the sensitivity and reproducibility. The optimised sensor showed good reproducibility (10% RSD calculated on three experiments repeated on the same electrode), whereas a reproducibility of 15% as RSD was calculated on electrodes from different preparations. Preliminary experiments carried out using glucose oxidase (GOD) as biorecognition element gave rise to promising results indicating that these new devices may represent interesting components for biosensor construction.