Selectivity and sensitivity of a reagentless electrochemical DNA sensor studied by square wave voltammetry and fluorescence.
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.
Laboratoire 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.
Steeve
S
Reisberg
Benoît
B
Piro
Vincent
V
Noel
Minh Chau
MC
Pham
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017404:In Situ Hybridization, Fluorescence / Q000295:instrumentation*; D007202:Indicators and Reagents; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D007202:Indicators and Reagents; D004247:DNA