An electrical DNA sensor with gold decorated SWCNT network

We report a novel electrical DNA biosensor, which consists of gold (Au) nano islands and SWCNT net on top of a semi-concentric Au electrode array (also referred to as the CGi). The real time measurement in TE buffer solution in a wide range of the target ss-DNA concentration down to fM (10^-15 M) was performed to check the detection limit. The CGi, functionalized with 25mer probe ss-DNA (5´-HSC₆-C₁₈-GC CAT TCT CAC CGH ATT CAG TCG TC-3´) shows high binding affinity of complementary ss-DNA targets until 10^-13 M. Moreover, it differentiates the mismatched target ss-DNA with high selectivity. This kind of CGi sensor platform can be applied to a target specific biological recognition element such as aptamer and protein easily, thereby realizing a general sensor platform for sensing many different types of biomolecules.