Macanovic A, Marquette C, Polychronakos C, Lawrence M F
Department of Chemistry and Biochemistry, Concordia University, 1455 de Maisonneuve W., Montreal, QC H3G 1M8, Canada.
Nucleic Acids Res. 2004 Jan 22;32(2):e20. doi: 10.1093/nar/gnh003.
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.
利用固定在Si/SiO₂芯片上的肽核酸（PNA）探针层，通过电化学阻抗测量来检测单链DNA序列。首先将环氧硅烷层固定在Si/SiO₂表面。固定过程包括PNA连接子的氨基与硅烷的环氧基之间的环氧/胺偶联反应。使用了一段20个核苷酸的PNA序列。阻抗测量能够检测在氧化物表面改性后，氧化物/溶液界面处电荷分布的变化。由于这些改性，固定和杂交后半导体的平带电位会发生显著偏移。根据检测核酸序列的经典方法，荧光测量结果支持了使用这种直接且快速的方法所获得的结果。
