Abstract: 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.