JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2019
·Vol. 166
·期 12
·B1028
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IF 3.12
Dandan Hu,Yufang Hu,Qingqing Zhang,Pingjian Ran,Xinda Liu,Yudi Zheng,Zhiyong Guo,Sui Wang,Di Wu
Monitoring DNA-related enzymes activity precisely and reliably is absolutely vital to better grasp their roles in the initiation and progression of cancer, thus further exploring their functions in cancer diagnosis and treat. Here, we establish a label-free electrochemical biosensor for investigating both terminal deoxynucleotidyl transferase (TdT) and exonuclease I (Exo I) activity by silver-based square wave stripping voltammetry (SWV). The strategy is achieved by two attractive points in design: a TdT-derived enzymatic synthesis of randomly arrayed C-rich DNA sequence and an Exo I-guided enzymatic degradation. This C-rich DNA-templated silver nanoclusters (AgNCs) serve as the electrochemical signal probe, and a signal on-off modulated process is displayed for the existence of TdT and Exo I, respectively. On account of AgNCs-based square wave stripping voltammetry, testing TdT has a linear concentration range of 0.001 to 5 U/mL with a detection limit of 0.00044 U/mL (S/N = 3). Additionally, Exo I with a detection limit of 0.027 U/mL (S/N = 3) can be analyzed with a linear range of 0.1 to 500 U/mL. The real application of the proposed method in their inhibitors screening is also discussed well. The biosensor provides a powerful idea for the ultrasensitive bio-analysis and shows broad clinical application prospect.
研究领域:
生物化学
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分析化学
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医学诊断
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产品关联
DOI
高影响因子
Biosensors-Basel
·
2022
·Vol. 12
·期 11
·989
·
IF 5.743
Aiting Cai,Luxia Yang,Xiaoxia Kang,Jinxia Liu,Feng Wang,Haiwei Ji,Qi Wang,Mingmin Wu,Guo Li,Xiaobo Zhou,Yuling Qin,Li Wu
An electrochemical-DNA (E-DNA) sensor was constructed by using DNA metallization to produce an electrochemical signal reporter in situ and hybridization chain reaction (HCR) as signal amplification strategy. The cyclic voltammetry (CV) technique was used to characterize the electrochemical solid-state Ag/AgCl process. Moreover, the enzyme cleavage technique was introduced to reduce background signals and further improve recognition accuracy. On the basis of these techniques, the as-prepared E-DNA sensor exhibited superior sensing performance for trace ctDNA analysis with a detection range of 0.5 fM to 10 pM and a detection limit of 7 aM. The proposed E-DNA sensor also displayed excellent selectivity, satisfied repeatability and stability, and had good recovery, all of which supports its potential applications for future clinical sample analysis.Keywords:DNA metallization;ctDNA;HCR;Exo Ι;E-DNA sensor
研究领域:
生物化学
·
分析化学
·
纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2022
·
IF 8.008
Guojuan Zhang,Yujie Han,Zhiguang Liu,Lifang Fan,Yujing Guo
A triple-amplified and ratiometric electrochemical aptasensor for CA125 was designed based on hemin–graphene/SH-β-cyclodextrin@PdPt nanoflower (H-Gr/SH-β-CD@PdPtNF) composites and an exonuclease I (Exo I)-assisted strategy. In the nanocomposite, hemin acts as an internal reference signal owing to the reversible heminox/heminred pair. PdPtNFs can significantly improve the electron transfer rate. SH-β-CD can efficiently enrich quercetin probes through host–guest recognition and increase the second indicator signal. In the presence of CA125, due to the specific binding between the aptamer and CA125, the conformational change of dsDNA (designed by the CA125 aptamer and its complementary DNA) results in the release of quercetin embedded in dsDNA. Subsequently, the free quercetin and DNA fragments are enriched on the H-Gr/SH-β-CD@PdPtNF-modified electrode. Thus, an enhanced oxidation peak from quercetin (IQ) and a reduced peak from hemin (Ihemin) can indicate the same biological identification event. In addition, the recycling amplification of CA125 by Exo I can effectively assist the increase of the quercetin signal. The value of IQ/Ihemin is linear with the concentration of CA125 in the range from 6.0 × 10–4 to 1.0 × 103 ng/mL, and the limit of detection is 1.4 × 10–4 ng/mL. The recovery of CA125 in human blood serum samples was from 99.2 to 104.4%. The proposed sensor is sensitive and reliable, which provides an avenue for the development of triple amplification and ratiometric signal strategies for detecting tumor markers in clinical diagnostics.
研究领域:
生物医学工程
·
临床诊断
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
·
2024
·
IF 5.6
Ming Li,Weipeng Teng,Wenying Lu,Mingna Sun,Jinsheng Duan,Xuchun Qiu
The improvement of dual-mode techniques was of particular interest to researchers, which might enhance the detection performance and applicability. Here, a dual-mode optical aptasensor (DO-aptasensor) platform based on exonuclease I (Exo I) cyclic digestion and synergistic enhancement strategy had proposed for zearalenone (ZEN). Following the preparation of dumbbell-shaped signal probe, the Exo I-based cyclic digestion amplification performed, and then the synergistic enhancement effect carried out to achieve the Poly-HRP-based colorimetry and FAM-SGI-based fluorescence. The efficient homogeneous system realized through the magnetic separation, while the signal interference further eliminated by the graphene oxide (GO). The LOD values were as low as 0.067 ng mL −1 for colorimetry mode and 0.009 ng mL −1 for fluorescence mode, which reduced 23-fold and 172-fold than ELASA by same ZEN-Apt. This promising platform gave rise to a dual-mode optical readout, improved sensitivity and positively correlated detection. Meanwhile, the DO-aptasensor also exhibited the acceptable specificity, desirable reliability and excellent practicability. This novel avenue of aptasensor platform hold great potential for dual-mode optical monitoring of other targets, which can further expand the application scope of Exo I-based signal amplification and synergistic enhancement effect.
研究领域:
分析化学
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生物传感器
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食品安全
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zhenjie Zheng,Jiarong Lin,Junyi Zhang,Fang Luo,Zuquan Weng,Jian Wang,Cuiying Lin,Bin Qiu,Zhenyu Lin,Hao Lin
Herein, we present the development of an ultra-sensitive immobilization-free homogeneous electrochemiluminescence (ECL) biosensor, leveraging the electrostatic repulsion between a negatively charged indium tin oxide (ITO) electrode and DNA and exonuclease I (Exo I)-powered signal amplification, to achieve highly efficient detection of thrombin. Specifically, the aptamer and the complementary DNA engage in the formation of a double-stranded DNA (dsDNA) complex. This negatively charged dsDNA structure subsequently associates with a positively charged ECL indicator, namely ruthenium phenanthroline (Ru(phen) 3 2+ ), resulting in the generation of the dsDNA-Ru(phen) 3 2+ ECL probe. The negatively charged dsDNA-Ru(phen) 3 2+ experiences electrostatic repulsion from the negatively charged ITO electrode, resulting in a low ECL signal. Nonetheless, upon the addition of thrombin, the aptamer preferentially binds to thrombin, triggering the releases of the embedded Ru(phen) 3 2+ facilitated by Exo I and hence resulting in a robust and enhanced ECL signal. The amplified ECL signal is linearly correlated with the logarithm of thrombin concentration within a detection range spanning from 10 fmol/mL to 50 pmol/mL, with a remarkable detection limit of 3.21 fmol/mL. This strategy eliminates the need for cumbersome labeling steps, avoids the electrode modification process, overcoming the low immobilization efficiency of aptamers and poor signal transduction of indicators labeled at the end of DNA.
研究领域:
生物传感技术
·
医学诊断
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
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