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Updated: Aug 9, 2026

Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
Selectivity and sensitivity of a reagentless electrochemical DNA sensor studied by square wave voltammetry and
Steeve Reisberg1, Benoît Piro, Vincent Noel
1Laboratoire Interfaces-Traitements-Organisation et Dynamique des Systèmes (ITODYS), Université Paris 7-Denis Diderot, associé au CNRS, UMR 7086, 1, rue Guy de la Brosse, 75005 Paris, France.
Abstract:
Poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-3-thioacetic acid-1,4-naphthoquinone)-modified electrode is used for the direct electrochemical detection of oligonucleotide hybridization. The polymer film presents well-defined electroactivity in the cathodic potential domain (between 0 and -0.8 V/SCE), due to the quinone group embedded into the polymer structure. The detection can be performed simply by square wave voltammetry. This sensor is a "signal-on" device and works with different oligonucleotide lengths, from 10 to 30 bases. Quantitative results from fluorescence are consistent with electrochemical data. It is confirmed that the signal increase in square wave voltammetry is unambiguously due to hybridization. The biosensor presents a detection limit of target of ca. 25 nM and is highly selective as it can discriminate single mismatch base.

