ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Baoting Dou,Hui Zhou,Xiguang Han,Po Wang
The dissociation of the walking strand from the track gives rise to decreased efficiency and long reaction time of DNA walkers. In this work, we constructed a DNA walker combining the introduction of a wedge segment with a bimetallic metal–organic framework (MOF) electrocatalyst to solve this problem. The target methylated DNA acted as a single-legged walker, and the immobilization probe assembled on the track contained a wedge segment that was complementary to the target methylated DNA persistently, inhibiting its dissociation from the track. The fuel strand modified with a bimetallic MOF would drive the target strand to conduct branch migration and move processively along the track. The stepwise movement of the target strand resulted in the loading of numerous bimetallic MOF catalysts to reduce H2O2 at the electrode interface, thereby a significantly increased current response would be obtained for the detection of methylated DNA. This DNA walker achieved a detection limit of 200 aM within 20 min and effectively distinguished DNA with different methylation statuses, which would pave a way for rapid and sensitive monitoring of DNA methylation.
研究领域:
生物化学
·
分析化学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Haohao Chen,Min Yuan,Fengqin Yin,Hui Cao,Xiuxiu Wu,Liling Hao,Weiyan Shi,Tai Ye,Fei Xu
The traditional nucleic acid-modified electrode in room-temperature manner suffers from the drawback of time-consuming and uneven distribution. In this work, we adopted the freeze-thawing method to construct a nicking enzyme-powered DNA walking machine on the gold electrode. In the absence of kanamycin, the intact substrate strand can trigger the self-assembly and form G4 nanowires on the electrode surface. After adding hemin, a significant catalytic current of the TMB oxidization can be observed. By contrast, once the specific binding between aptamer and kanamycin occurs, the activated walking strand processes a consecutive binding-cleavage cycle with the substrate strand on the electrode surface. The residue substrate fragment is unable to trigger the subsequent G-quadruplex assembly, resulting in a decrease in catalytic current. Under optimal experimental conditions, a linear relationship between the kanamycin concentration and current decrease was obtained in the range from 5 to 100 pM, and the limit of detection was 1.44 pM. This method has also demonstrated practical performance in the spiked milk and honey with satisfactory recoveries of 107.1 % to 114.3 % and 94.3 % to 101.5 %, respectively.
研究领域:
生物化学
·
分析化学
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 12
·1-8
·
IF 6.232
Yang Zongqi,Liu Mei,Li Baoxin
A DNAzyme-powered DNA walking machine was constructed to develop the fluorescence aptasensing for sensitive detection of kanamycin. The aptamer for kanamycin is partially hybridized with complementary DNA (cDNA) modified on magnetic beads (MBs). The specific interaction of target and aptamer triggered the cDNA to be free tentatively, which captured walker DNA. Then the autonomous motion of DNA walker on MBs surface was propelled via DNAzyme digestion of recognition sites. The signal probe was separated, and the amplified fluorescence signal was achieved by the accumulation of the signal probe. Kanamycin was used as a model analyte, and the developed assay achieves a detection limit of 0.00039 ng·mL −1 (S/ N = 3) within a linear detection range from 0.001 to 2000 ng·mL −1 . This aptasensing strategy can be extended for detection of other antibiotics by adapting corresponding target recognition aptamer sequence.
Graphical abstract The fluorescence aptasensing for sensitive detection of kanamycin based on DNAzyme-powered DNA walking machine was constructed.
研究领域:
分析化学
·
生物传感器
·
分子诊断
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DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Kai Wang,Xiaohai Yan,Jiamin Wu,Jianrui Qi,Mengge Ning,Menghui Li,Rui Sun,Zhouli Wang,Yahong Yuan,Tianli Yue
Deoxynivalenol (DON) contamination in cereals is a widespread issue with global implications, necessitating the development of efficient detection methods. Here, a fluorescent aptasensor integrating target-responsive DNA three-way junction (TWJ) and DNA walking machine was developed to detect DON. The DON-specific aptamer (Apt) and the walker (Walker DNA) are integrated into TWJs. TWJs initiate the DNA walking machine with the assistance of Nb. Bbv CI to provide signal amplification for sensing events. The constructed fluorescent aptasensor selectively recognizes and detects DON. Additionally, the sensing platform explored the quantitative relationship between fluorescence signal changes and DON concentration, achieving a limit of detection (LOD) of 0.009 ng/mL. Ultimately, the method performed well in the detection of cornmeal samples with recoveries ranging from 95.49 % to 100.82 %. The method demonstrates good stability and is expected to be a potential candidate for the accurate detection of DON in grains.
研究领域:
食品科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2022
·
IF 12.545
Jialin Zhang,Yaqi Fan,Jinhui Li,Bin Huang,Herui Wen,Jiali Ren
The key factor to control the incidence rate of diseases caused by bacteria is rapid detection and early diagnosis. Herein, we proposed a new electrochemical bacterial sensor by coupling DNA walking and rolling circle amplification (RCA) reaction-assisted “silver-link” crossing electrode. Staphylococcus aureus ( S. aureus ) was detected using this proof-of concept strategy. Aptamer/DNA walker and auxiliary sequence (AS)/RCA reaction probe (RP) duplexes were modified on the electrode surface . The binding of S. aureus with its aptamer caused the disintegration of aptamer/DNA walker and released DNA walker. With the help of Exo III, DNA walker moved along the electrode surface and AS in AS/RP duplex was continuously digested to release RP. By introducing phi29 DNA polymerase, RCA reaction was performed using RP as the reaction primer to form long single-strand RCA extension products between the electrodes. The “silver-link” crossing electrode was formed by metallization of “gene-link”, significant conductivity was thus acquired for bacteria detection . The limit of detection (LOD) was 10 CFU/mL and detection time was 2 h. The proposed sensor has high efficiency, good stability and low background signal, human serum and milk samples were successfully detected, which emerged a promising potential in the food monitoring and clinical diagnosis.
研究领域:
生物传感器
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分子诊断
·
食品监测
·
临床诊断
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Yihan Wang,Jinfeng Quan,Jialei Zhang,Kejing Huang,Xuemei Wang,Hui Jiang
The fragments of molecular motors can be transported and operated autonomously along a track. Most molecular walker systems are assembled from DNA building modules, exhibiting great potential applications in biocomputing, drug transport, sensing, etc. Hereby, we report a DNA walker driven by endonuclease Nt.BbvC I that can autonomously induce “signal off” sensing platform for highly sensitive detection of tumor cells. DNA density and trajectory conformation can affect DNA walker properties. Molybdenum selenide@gold nanoparticles (MoSe 2 @AuNPs) are modified on the electrode surface as a scaffold to accommodate more hairpin probe (H1) and provide a good interface for DNA walking. Magnetic beads are used to enrich target tumor cells, release single-stranded DNA (S1) and trigger DNA walker-based amplification strategy. Upon addition of tumor cells, more DNA-methylene blue (DNA-MB) is cracked from the electrode surface. Benefiting from efficient electrode modification, magnetic enrichment, DNA walker and enzyme-assisted amplification, an ultra-high sensitivity electrochemical cell analysis is realized, with a detection limit of 2 cells mL −1 . More importantly, this DNA walker strategy is available for tumor cell analysis in clinical samples, suggesting the potential diagnostic applications.
研究领域:
生物传感
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分子生物学
·
医学诊断
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产品关联
DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Qisheng Luo,Zhili Qiu,Hongqu Liang,Fa Huang,Chen Wei,Jiuying Cui,Zichun Song,Qianli Tang,Xianjiu Liao,Zhao Liu,Jiangbo Wang,Fenglei Gao
α-synuclein oligomer is a marker of Parkinson's disease. The traditional enzyme-linked immunosorbent assay for α-synuclein oligomer detection is not conducive to large-scale application due to its time-consuming, high cost and poor stability. Recently, DNA-based biosensors have been increasingly used in the detection of disease markers due to their high sensitivity, simplicity and low cost. In this study, based on the DNAzyme-driven DNA bipedal walking method, we developed a signal-on electrochemical sensor for the detection of α-syn oligomers. Bipedal DNA walkers have a larger walking area and faster walking kinetics, providing higher amplification efficiency compared to conventional DNA walkers. The DNA walker is driven via an Mg 2+ -dependent DNAzyme, and the binding-induced DNA walker will continuously clamp the MB, resulting in the proliferation of Fc confined near the GE surface. The linear range and limit of detection were 1 fg/mL to 10 pg/mL and 0.57 fg/mL, respectively. The proposed signal-on electrochemical sensing strategy is more selective. It will play a significant role in the sensitive and precise electrochemical analysis of other proteins.
研究领域:
生物医学工程
·
分析化学
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产品关联
DOI
PubMed
高影响因子
ANALYST
·
2021
·Vol. 146
·期 18
·5643-5649
·
IF 4.616
Li Tan,Jiangnan Lu,Xin Wang,Guang Liu,Xiaomei Mu,Kun Hu,Shulin Zhao,Jianniao Tian
Highly specific and ultrasensitive detection of uracil-DNA glycosylase (UDG) activity is of great significance for maintaining genomic integrity and medical research of related diseases. Here, we constructed a random DNA walking nanomachine based on a DNAzyme for UDG activity detection on the AuNP (Au nanoparticle) surface. When UDG is present, the U bases in the Y structure are removed, resulting in AP sites, which will be cleaved by Endo-IV to generate a 3′ concave end for Exo-III, causing the locking strand of the DNAzyme to be completely hydrolyzed by the Exo-III and release the walking strand to randomly pair with the substrate strand on the AuNP surface; then, the walking strand exerts its cleavage activity with the assistance of Mg2+ to cleave the substrate strand and keep the fluorophore 6-carboxyfluorescein (FAM) away from the surface of the AuNP, which restores the fluorescence signal of this system. In this way, sensitive detection of UDG can be realized, and the detection limit is as low as 3.69 × 10−6 U mL−1. In addition, we found that this method is highly specific to UDG and can be used to detect UDG specifically in complex samples, which has certain application prospects in biomedical research and clinical diagnosis related to UDG.
研究领域:
分子生物学
·
纳米技术
·
生物医学工程
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
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