کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10429476 | 909794 | 2011 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A label-free electrochemical DNA sensor based on exonuclease III-aided target recycling strategy for sequence-specific detection of femtomolar DNA
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The present work demonstrates a rapid, single-step and ultrasensitive label-free and signal-off electrochemical sensor for specific DNA detection with excellent discrimination ability for single-nucleotide polymorphisms, taking advantage of Exonuclease III (Exo III)-aided target recycling strategy to achieve signal amplification. Exo III has a specifical exo-deoxyribonuclease activity for duplex DNAs in the direction from 3â² to 5â² terminus, however its activity on the duplex DNAs with 3â²-overhang and single-strand DNA is limited. In response to the specific features of Exo III, the proposed E-DNA sensor is designed such that, in the presence of target DNA, the electrode self-assembled signaling probe hybridizes with the target DNA to form a duplex in the form of a 3â²-blunt end at signaling probe and a 3â²-overhang end at target DNA. In this way, Exo III specifically recognizes this structure and selectively digests the signaling probe. As a result, the target DNA dissociates from the duplex and recycles to hybridize with a new signaling probe, leading to the digestion of a large amount of signaling probes gradually. A redox mediator, Ru(NH3)63+ (RuHex) is employed to electrostatically adsorbed onto signaling probes, which is directly related to the amount and the length of the signaling probes remaining in the electrode, and provides a quantitative measure of sequence-specific DNA with the experimentally measured (not extrapolated) detection limit as low as 20Â fM. Moreover, this E-DNA sensor has an excellent differentiation ability for single mismatches with fairly good stability.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biosensors and Bioelectronics - Volume 28, Issue 1, 15 October 2011, Pages 232-238
Journal: Biosensors and Bioelectronics - Volume 28, Issue 1, 15 October 2011, Pages 232-238
نویسندگان
Di Wu, Bin-Cheng Yin, Bang-Ce Ye,