An electrochemical supersandwich assay for sensitive and selective DNA detection in complex matrices

In a traditional sandwich assay, a DNA target hybridizes to a single copy of the signal probe. Here we employ a modified signal probe containing a methylene blue (a redox moiety) label and a “sticky end.” When a DNA target hybridizes this signal probe, the sticky end remains free to hybridize another target leading to the creation of a supersandwich structure containing multiple labels. This leads to large signal amplification upon monitoring by voltammetry.

Xia, F., White, R., Zuo, X., Patterson, A., Xiao, Y., Kang, D., Gong, X., Plaxco, K., Heeger
Journal of the American Chemical Society
Volume: 132
Pages: 14346–14348
Date: September, 2010
ICB Affiliated Authors: Alan J Heeger, Kevin W Plaxco