期刊
ELECTROCHEMISTRY COMMUNICATIONS
卷 7, 期 4, 页码 416-420出版社
ELSEVIER SCIENCE INC
DOI: 10.1016/j.elecom.2005.02.015
关键词
self-assembled monolayer; gold electrode; DNA; label-free; hybridization detection
Unlabeled hairpin and linear DNA probes have been immobilized on polycrystalline gold electrodes by forming mixed SAMs of thiolated single-stranded oligonucleotides (HS-ssDNA) and a spacer thiol (4-mereaptobutan-1-ol) by spontaneous coadsorption. Chronocoulometry was used to determine the amount of DNA present in the mixed SAM. It was found that linear ssDNA achieves a higher surface concentration compared to hairpin ssDNA under the same deposition conditions. The hybridization behaviour of these SAMs was analysed by impedance spectroscopy in the presence of [Fe(CN)(6)](3-/4-). Addition of the complementary oligonucleotide to the linear ssDNA modified gold electrode resulted in an increase of the electron transfer resistance R-ct, while it decreased in the case of the hairpin DNA probe. These results are due to the smaller surface coverage and the conformational change of the DNA hairpin probe upon hybridization. Hybridization experiments with a non-complementary sequence resulted in no change of the impedance spectra. (c) 2005 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据