کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7231087 | 1470953 | 2016 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ultraspecific electrochemical DNA biosensor by coupling spontaneous cascade DNA branch migration and dual-signaling sensing strategy
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
Using spontaneous cascade DNA branch migration and dual-signaling sensing strategy, we developed a novel universal electrochemical biosensor for the highly specific and sensitive detection of nucleic acids. A target strand (Ts) competitively hybridized with a ferrocene (Fc)-labeled signal probe (Fc-S1), which was blocked by a protector strand (Ps), after strand displacement to form the Ts/Fc-S1 duplex. A methylene blue (MB)-modified signal probe (MB-S2) was immobilized on the Au electrode surface by hybridizing with a thiolated capture probe (Cp). Then, the obtained reactants (Ts/Fc-S1 and MB-S2/Cp) suffered spontaneous DNA branch migration and produced two hybridization products (Fc-S1/Cp and MB-S2/Ts). These reactions led to the dissociation of MB molecules and the collection of Fc molecules. The detection mechanism of this DNA biosensor involved distance variation between the redox tags and the Au electrode, which was associated with target-induced cascade DNA branch migration. Moreover, we rationally designed the cascade DNA branch migration to occur spontaneously with ÎG°â0, at which slight thermodynamic changes caused by base mismatch exerted a disproportionately large effect on the hybridization yield. This “signal-on/off” sensing system exhibited a remarkable analytical performance and an ultrahigh discrimination capability even against a single-base mismatch. The maximum discrimination factor (DF) of base mutations or alterations can reach 17.9. Therefore, our electrochemical biosensor might hold a great potential for further applications in biomedical research and early clinical diagnosis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biosensors and Bioelectronics - Volume 78, 15 April 2016, Pages 464-470
Journal: Biosensors and Bioelectronics - Volume 78, 15 April 2016, Pages 464-470
نویسندگان
Ting Wang, Lili Zhou, Shulian Bai, Zhang Zhang, Junlong Li, Xiaoying Jing, Guoming Xie,