Functionalized multi-wall carbon nanotubes as an efficient additive for electrochemical DNA sensor

Functionalized multi-wall carbon nanotubes (FMWCNTs) were used as an additive in electrochemical DNA sensor to modulate the electrochemical current depending on the sequence of the target DNA. This DNA sensing system was simplistically generated by mixing the constituents in a buffer solution, and exhibited good DNA sequence differentiation ability. Compared to the previously reported functionalized graphene (FG) additive, the sample preparation time was reduced from 4 h and 20 min to 1 h, and the detection limit (141.2 pM) was reduced by more than two orders of magnitude. When FMWCNT and FG were fabricated via the same functionalization process, suspended FMWCNT sank more rapidly in solution than FG, leading to a shorter reaction time and better DNA detection ability than that obtained with the FG additive.