Single gene differentiation by DNA-modified carbon electrodes using an AC impedimetric approach.
Anal Chem
; 79(3): 1153-7, 2007 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-17263348
ABSTRACT
A simple and novel electrochemical biosensor is described for differentiating between differing gene sequences on the basis of DNA hybridization events. Polyethylenimine-modified screen-printed carbon electrodes were used to immobilize single-stranded PCR fragments from plasmid DNA from the gene for pyruvate kinase. AC impedimetric measurements were first performed on these systems in buffer and then upon exposure to single-stranded DNA. When the electrode and solution DNA were complementary, a large drop in impedance was measured. Complementary DNA could be clearly detected at concentrations down to 1 fg/mL. Higher concentrations gave faster hybridization with saturation occurring at levels above 1 ng/mL. Responses were much lower upon exposure to noncomplementary DNA, even at higher concentrations, with the sensor showing a high degree of selectivity. This sensor format offers great promise for many DNA hybridization applications and lends itself to mass fabrication.
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Base de dados:
MEDLINE
Assunto principal:
Sequência de Bases
/
Técnicas Biossensoriais
/
Eletrodos
/
Hibridização de Ácido Nucleico
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article