Electrochemical monitoring of indicator-free DNA hybridization by carbon nanotubes-chitosan modified disposable graphite sensors

► Single walled carbon nanotubes (SWCNT)-chitosan (CHIT) modified pencil graphite electrodes (PGEs) were developed as the first time in this study for electrochemical monitoring of Hepatitis B virus (HBV) DNA sequence selective hybridization. ► 41.2% signal enhancement was observed by using CHIT-CNT-PGEs in contrast to the signals observed by unmodified PGE. ► It was found that Hepatitis B virus (HBV) DNA probe immobilized CHIT-CNT modified disposable electrodes exhibit better selectivity and specificity for the label-free monitoring of sequence specific HBV DNA.