ANALYST
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2015
·Vol. 140
·期 19
·6660-6670
·
IF 4.107
Qing Zheng,Hao Wu,Zongxu Shen,Wenyu Gao,Yu Yu,Yuehui Ma,Weijun Guang,Quangui Guo,Rui Yan,Junzhong Wang,Kejian Ding
A label-free electrochemical DNA sensor was fabricated by deposition of polyaniline and pristine graphene nanosheet (P/Gratios) composites in different mass ratios, DNA probe and bovine serum albumin (BSA) layer by layer on the surface of a glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS) was employed to monitor every step of fabrication of P/Gratio-based DNA sensors and to evaluate the detection results in terms of the hybridization of complementary DNA, mutant DNA and non-complementary DNA. The results illustrate that the P/Gratio-based DNA sensor could highly efficiently detect complementary DNA from 0.01 pm to 1 μm and discriminate single-nucleotide polymorphisms (SNPs). In the process of detection, double-stranded DNA (dsDNA), resulting from hybridization of a DNA probe, escaping from or remaining on the sensor surface, was monitored by changing the ratio of polyaniline (PANI) to graphene, which was decided by the competition between the electrostatic interaction and Brownian motion.
研究领域:
生物化学
·
纳米材料科学
·
分子诊断学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Hong Guo Chen,Wang Ren,Jing Jia,Ji Feng,Zhong Feng Gao,Nian Bing Li,Hong Qun Luo
We describe here a fluorometric assay for sensitive detection of oligonucleotides , based on a target recycling amplification strategy driven by toehold-mediated strand displacement reaction and on exonuclease III (Exo Ш)-assisted fluorescence background suppression strategy. The network consists of a pair of partially complementary DNA hairpins (HP 1 and HP 2 ) with 3′ overhang ends, between which the spontaneous hybridization is kinetically hindered by the stems. The target DNA is repeatedly used to trigger a recycling progress between the hairpins, generating numerous HP 1 –HP 2 duplex complexes. Exo III was then employed to digest the double strand parts of the residual hairpins and the intermediate products. The fluorescent dye , SYBR Green I , binds to the double-strand DNA products and emits strong fluorescence to achieve sensitive detection of the target DNA with the detection limit of 5.34 pM. Moreover, this proposed strategy showed high discrimination efficiency towards target DNA against mismatched DNA and was successfully applied in the analysis of human serum sample.
研究领域:
生物化学
·
分子生物学
·
分析化学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Fang Hu,Wancun Zhang,Wei Meng,Yuxiang Ma,Xianwei Zhang,Ying Xu,Peng Wang,Yueqing Gu
Single nucleotide polymorphisms (SNPs) are crucial during the early diagnosis of a given disease as well as in evaluating their response to certain drugs. Thus, this study sought the development of ferrocene (Fc)-labeled electrochemical biosensor for SNP detection. This proposed system involves the ligation of four short probes (e.g., A, B, A′, and B′, where B′ is labeled with an Fc-tag) in the presence of target DNA via ligase chain reaction (LCR), resulting in the formation of Fc-tagged duplex AB-A′B′ in 2 n . Subsequently, immobilization of the Fc-tagged duplex AB-A′B′ on a single-stranded DNA capture probe (SC-DNA)-carboxyl multi-wall carbon nanotube (MWCNT-COOH) modified glassy carbon electrode (GCE) was accomplished through hybridization. Owing to the specificity of hybridization, and the use of Fc as electrochemical probe for detection of duplex AB-A′B′, such strategy realized directly analysis of LCR products without the need for purification . By taking advantage of the thermal stability and high-discrimination ability of HiFi Taq DNA ligase for single-base differences, the specificity of hybridization, the EGFR T790 M mutant DNA (MT-DNA) biosensor was developed to offer a low limit of detection (0.75 aM), a high discrimination of single-base mismatches [as low as 0.01% (molar fraction)], a wide linear range of more than 7 orders of magnitude (1 aM–10 pM), and the recovery rates (95.3%–107.8%) from human serum samples. Thus, the biosensor under development was found to be economical, highly-sensitive, and exceptionally selective for detection of SNPs, and as well as extending the versatile applications of LCR to offer great potential for diagnosis and individual clinical regimens.
研究领域:
生物化学
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生物技术
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分析化学
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分子生物学
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医学诊断
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）