Preparation of a SWCNT–DNA modified electrode and its electrochemical detection property

SWCNT-DNA hybrids were prepared by a self-assembly process of SWCNTs and single strand DNA(ssDNA) and all nanotubes were isolated into individual nanotubes in these hybrids.The SWCNT-DNA hybrids attach strongly to a glassy carbon(GC) electrode surface and easily form a uniform film,to produce a SWCNT-DNA modified electrode.Compared with unmodified and bundled SWCNT modified GC electrodes,the SWCNT-DNA modified one shows strong current signals responding to a K3Fe(CN)6 solution in the cyclic voltammetric analysis.Moreover,such electrochemical signals are stable,and of high sensitivity and respond to the concentration of K3Fe(CN)6 solution in a linear relationship.In the SWCNT-DNA modified electrode,the wrapping of ssDNA around the SWCNT increases the specific surface area and enhances electron transfer in the Fe(CN)3-6/ Fe(CN)4-6system,indicating that this novel electrode could be a promising candidate for electrochemical detection.