title: Impedance-based detection of DNA sequences using a silicon transducer with PNA as the probe layer.
abstract: Electrochemical impedance measurements were used for the detection of single-strand DNA sequences using a peptide nucleic acid (PNA) probe layer immobilized onto Si/SiO2 chips. An epoxysilane layer is first immobilized onto the Si/SiO2 surface. The immobilization procedure consists of an epoxide/amine coupling reaction between the amino group of the PNA linker and the epoxide group of the silane. A 20-nucleotide sequence of PNA was used. Impedance measurements allow for the detection of the changes in charge distribution at the oxide/solution interface following modifications to the oxide surface. Due to these modifications, there are significant shifts in the semiconductor's flat-band potential after immobilization and hybridization. The results obtained using this direct and rapid approach are supported by fluorescence measurements according to classical methods for the detection of nucleic acid sequences.
authors.affiliation: Department of Chemistry and Biochemistry, Concordia University, 1455 de Maisonneuve W., Montreal, QC H3G 1M8, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Macanovic
authors.forename: C
authors.initials: C
authors.lastname: Marquette
authors.forename: C
authors.initials: C
authors.lastname: Polychronakos
authors.forename: M F
authors.initials: MF
authors.lastname: Lawrence
mesh_terms: D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D017097:Electric Impedance; D009693:Nucleic Acid Hybridization / Q000379:methods; D015345:Oligonucleotide Probes / Q000737:chemistry; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D015203:Reproducibility of Results; D012666:Semiconductors; D012825:Silicon / Q000737:chemistry*; D014159:Transducers
chemical_list: D004277:DNA, Single-Stranded; D015345:Oligonucleotide Probes; D020135:Peptide Nucleic Acids; D004247:DNA; D012825:Silicon