Electrochemical Characterization of O-2 Plasma Functionalized Multi-Walled Carbon Nanotube Electrode for Legionella pneumophila DNA Sensor

Abstract

An electrochemical DNA sensor for Legionella pneumophila detection was constructed using O-2 plasma functionalized multi-walled carbon nanotube (MWCNT) film as a working electrode (WE) The cyclic voltammetry (CV) results revealed that the electrocatalytic activity of plasma functionalized MWCNT (pf-MWCNT) significantly changed depending on O-2 plasma treatment time due to some oxygen containing functional groups on the pf-MWCNT surface Scanning electron microscope (SEM) images and X-ray photoelectron spectroscopy (XPS) spectra were also presented the changes of their surface morphologies and oxygen composition before and after plasma treatment From a comparison study, it was found that the pf-MWCNT WEs had higher electrocatalytic activity and more capability of probe DNA immobilization, therefore, electrochemical signal changes by probe DNA immobilization and hybridization on pf-MWCNT WEs were larger than on Au WEs The pf-MWCNT based DNA sensor was able to detect a concentration range of 10 pM-100 nM of target DNA to detect L pneumophila (C) 2010 The Japan Society of Applied Physics