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Journal of Nanomaterials
Volume 2015, Article ID 407184, 9 pages
Research Article

A Universal Fast Colorimetric Method for DNA Signal Detection with DNA Strand Displacement and Gold Nanoparticles

1Department of Obstetrics and Gynecology, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
2College of Computer and Communication Engineering, China University of Petroleum, Qingdao, Shandong 266580, China
3Faculty of Engineering, Computing and Science, Swinburne University of Technology, 93350 Kuching, Sarawak, Malaysia
4Key Laboratory of Image Information Processing and Intelligent Control, School of Automation, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China

Received 6 May 2015; Revised 7 July 2015; Accepted 8 July 2015

Academic Editor: Xuping Sun

Copyright © 2015 Xin Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


DNA or gene signal detection is of great significance in many fields including medical examination, intracellular molecular monitoring, and gene disease signal diagnosis, but detection of DNA or gene signals in a low concentration with instant visual results remains a challenge. In this work, a universal fast and visual colorimetric detection method for DNA signals is proposed. Specifically, a DNA signal amplification “circuit” based on DNA strand displacement is firstly designed to amplify the target DNA signals, and then thiol modified hairpin DNA strands and gold nanoparticles are used to make signal detection results visualized in a colorimetric manner. If the target DNA signal exists, the gold nanoparticles aggregate and settle down with color changing from dark red to grey quickly; otherwise, the gold nanoparticles’ colloids remain stable in dark red. The proposed method provides a novel way to detect quickly DNA or gene signals in low concentrations with instant visual results. When applied in real-life, it may provide a universal colorimetric method for gene disease signal diagnosis.