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Updated: Jun 8, 2026

Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
An electrochemical supersandwich assay for sensitive and selective DNA detection in complex matrices
Fan Xia1, Ryan J White, Xiaolei Zuo
1Center for Polymers and Organic Solids, University of California, Santa Barbara, California 93106, USA.
None:
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.
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