Amplified electrocatalysis at DNA-modified nanowires for ultrasensitive biosensing

Three-dimensional gold nanowire ensembles (NEE) are a novel and useful platform for electrochemical DNA detection. Work performed in our laboratory using the three-dimensional nanostructures with an electrocatalytic reporter system has produced attomole sensitivity towards target DNA sequences. Large electrocatalytic signals observed at DNAmodified nanowires produce high signal-to-noise ratios, which is one factor that contributes to the improved sensitivity. DNA-modified nanostructures generate amplified electrocatalysis signals that are significantly larger than those observed at bulk gold surfaces, and our experiments indicate that the three-dimensional architectures of the nanowires facilitate the electrocatalytic reaction because of enhanced diffusion and accessibility occurring around these structures. The heightened sensitivity achieved indicates that the nanowire ensembles constitute a promising platform for ultrasensitive biosensors.