Label-free DNA hybridization probe based on a conducting polymer.
A new approach to the realization of the electrochemical DNA hybridization probe is described. It is based on the exchange of chloride ion between the polypyrrole layer and the buffer. The shape of the cyclic voltammogram is modulated by the negative charge density at this interface, resulting from the immobilized target DNA. The negative charge density increases when the complementary DNA hybridizes with the probe DNA. The hybridization event can be clearly seen in the cyclic voltammogram before and after the addition of the probe DNA. The immobilization is accomplished via the Mg2+ bridging complex between phosphonic acid groups of the poly[2,5-dithienyl-(N-3-phosphorylpropyl)pyrrole] grafted at the polypyrrole surface and the phosphate groups of the target DNA.
Thompson
Liz A
LA
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Kowalik
Janusz
J
Josowicz
Mira
M
Janata
Jiri
J
D015342:DNA Probes / Q000737:chemistry*; D018076:DNA, Complementary / Q000737:chemistry; D004277:DNA, Single-Stranded / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D015636:Magnesium Chloride / Q000737:chemistry; D009693:Nucleic Acid Hybridization / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D055672:Static Electricity
D015342:DNA Probes; D018076:DNA, Complementary; D004277:DNA, Single-Stranded; D011108:Polymers; D011758:Pyrroles; D015636:Magnesium Chloride; C067635:polypyrrole