SENSORS
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2013
·Vol. 13
·期 1
·1064-1075
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IF 1.953
Zhenzhu Zheng,Jing Han,Wensheng Pang,Juan Hu
With an internal transcribed spacer of 18 S, 5.8 S and 26 S nuclear ribosomal DNA (nrDNA ITS) as DNA marker, we report a colorimetric approach for authentication ofPseudostellaria heterophylla(PH) and its counterfeit species based on the differentiation of the nrDNA ITS sequence. The assay possesses an unlabelled G-quadruplex DNAzyme molecular beacon (MB) probe, employing complementary sequence as biorecognition element and 1:1:1:1 split G-quadruplex halves as reporter. In the absence of target DNA (T-DNA), the probe can shape intermolecular G-quadruplex structures capable of binding hemin to form G-quadruplex-hemin DNAzyme and catalyze the oxidation of ABTS2−to blue-green ABTS•−by H2O2. In the presence of T-DNA, T-DNA can hybridize with the complementary sequence to form a duplex structure, hindering the formation of the G-quadruplex structure and resulting in the loss of the catalytic activity. Consequently, a UV-Vis absorption signal decrease is observed in the ABTS2−-H2O2system. The “turn-off” assay allows the detection of T-DNA from 1.0 × 10−9to 3.0 × 10−7mol·L−1(R2= 0.9906), with a low detection limit of 3.1 × 10−10mol·L−1. The present study provides a sensitive and selective method and may serve as a foundation of utilizing the DNAzyme MB sensor for identifying traditional Chinese medicines.Keywords:G-quadruplex DNAzyme;molecular beacon;colorimetric;Pseudostellaria heterophylla
研究领域:
生物化学
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分子生物学
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分析化学
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中药学
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PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
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2015
·
IF 6.409
Hui Zhang,Meixing Li,Caihong Li,Zhihui Guo,Huilei Dong,Ping Wu,Chenxin Cai
The expression profile of vascular endothelial growth factor (VEGF) is highly correlated with the occurrence and development of cancer. This work reports an electrochemiluminescence (ECL) approach for highly sensitive detection of VEGF 165 . This approach comprises aptamer–target recognition, T7 exonuclease (T7 Exo)-assisted cycling signal amplification and efficient quenching of ECL of CdS:Eu nanocrystals (NCs) by using DNAzyme. In this assay, CdS:Eu NCs were used as the ECL substrate, A guanine (G)-rich single-stranded DNA (ssDNA) sequence and VEGF 165 aptamer were co-immobilized on the surface of the CdS:Eu NCs modified glassy carbon electrode. After recognition and binding to VEGF 165 , the aptamer moved away from the electrode surface and induced the proposed cyclic cleavage of the target DNA with T7 Exo. A large amount of G-rich ssDNA was released on the CdS:Eu film and folded into G-quadruplex/hemin DNAzyme in the presence of hemin and K + , consequently decreasing the ECL intensity of CdS:Eu. A good linearity was obtained for VEGF 165 detection within the range of 1 pM to 20 nM with a detection limit of 0.2 pM. This assay could be a universal and promising protocol for detection of various biomarkers for early clinical diagnosis.
研究领域:
生物化学
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医学诊断
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纳米技术
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DOI
PubMed
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2022
·
IF 4.598
Kaiyue Hu,Lingxia Qin,Xinxin Ren,Zhiyong Guo,Sui Wang,Yufang Hu
Lead ion (Pb 2+ ) exposure is a serious hazard to human health, and its detection is still faced with undesirable bottleneck problems (poor sensitivity/selectivity and insufficient accuracy). Herein, a new dual-mode analytical platform for Pb 2+ assay is developed by integrating electrochemical (EC) with electro-chemiluminescent (ECL) system. It all starts with the shearing action of Pb 2+ to Pb 2+ -special DNAzyme (Pb-DNAzyme), and the substrate strand is cleaved at its cleavage site to result in two pieces of DNA, which are employed separately to construct the expected dual-mode biosensor. Interestingly, for EC mode, the Pb 2+ act as not only the target but also the inducing factor of the formation of in-situ G4 nanostructure, and the SWV technique is taken to achieve the signal output of the stacked crystal violet molecules. Furtherly, the other released DNAs can be captured by the three handing sides of DNA nano-prism, and trigger subsequently the opening of DNA hybridization chain reaction; then the designed free three bases can bring about TdT polymeric reaction; finally, by taking advantage of DNA nanoprobe, the dual-mode biosensor is developed successfully with the detection limit of 3.6 pM (EC) or 0.23 pM (ECL) (3δ/slope), which is much lower than the previous reports. This co-operative dual-mode method is also investigated for the analysis of Pb 2+ in the serum and lake water samples with acceptable results, presenting great potential applications in the future.
研究领域:
生物化学
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分析化学
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环境科学
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DOI
高影响因子
Chemistry-Switzerland
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2023
·Vol. 5
·期 3
·1497-1507
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IF 2.1
Longlong Gao,Rui Tian,Yong Shao
DNAzymes have attracted increasing interest in developments of gene tools, therapies, and biosensors. Among them, G-quadruplexes are widely used as the key structure elements of DNAzymes to activate the catalytic competency of specific cofactors, such as hemin, but there is a great demand to diversify DNAzymes using other more straightforward DNA structures such as fully matched duplex (FM-DNA). However, the perfect base pairs in duplex limit the DNAzyme activity. In this work, a photocatalytic DNAzyme was developed by introducing an abasic site (AP site) into duplex (AP-DNA) to switch its photocatalytic activity. Palmatine (PAL), a photosensitizer from natural isoquinoline alkaloids, served as a cofactor of the DNAzyme by binding at the AP site. The AP site provides a less polarized environment to favor the PAL fluorescence. As a result, dissolved oxygen was converted into singlet oxygen (1O2) via energy transfer from the excited PAL. The oxidation of substrates by the in situ photogenerated1O2served as a readout for the DNAzyme. In addition, the duplex-based DNAzyme was engineered from FM-DNA by the cascade uracil-DNA glycosylase to generate AP-DNA. Our work provides a new way to construct duplex-based DNAzymes.Keywords:DNAzyme;duplex;abasic site;phohocatalysis;isoquinoline alkaloids;palmatine
研究领域:
生物化学
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分子生物学
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催化
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高影响因子
ANALYTICA CHIMICA ACTA
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2023
·
IF 6.2
Dongyan Li,Yuxiong Lv,Huaiyue Xia,Jing Huang,Wenjie Liu,Jianna Yu,Guoxing Jing,Wen Liu,Yingying Sun,Wenshan Li
Sensitivity and selectivity are critical parameters to evaluate the performance of sensors. For trace detection, it remains a challenge to design a new sensor that achieves high sensitivity and selectivity simultaneously. Here, we present a target-activated dual Mg 2+ -dependent DNAzyme (MNAzyme) that served as a simple sensing model to explore the multivalency in improving the analytical sensitivity and selectivity for target detection. Mercury ion (Hg 2+ ), a notorious toxic metal ion , was selected as a model target. In the presence of Hg 2+ , the thymine-rich regions of the hairpin probe and primer could hybridize to form a stable duplex via the thymine-Hg 2+ -thymine structure. Then, an intact enzyme sequence was exposed and two separate enzyme fragments were close to each other, generating a dual MNAzyme. Benefiting from the localized high-concentration of the enzyme strand, the dual MNAzyme showed a remarkable improvement in binding stability. The catalytic rate constant of the dual MNAzyme was theoretically 1.60 times higher than that of the monomeric counterpart, and the sensitivity and selectivity had 4.50 and 1.44-fold enhancement, respectively. When the dual MNAzyme was used for sensor applications , the limit of detection was determined to be 0.04 and 0.2 nM via UV–vis spectrophotometer and naked eye, respectively. Meanwhile, the method offered desirable selectivity toward Hg 2+ against other metal ions. With the advantages of simple operation, high sensitivity, and desirable selectivity, the developed multivalent sensing platform could be easily expanded in the future for the on-site detection of other low-abundance analytes.
研究领域:
生物化学
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环境科学
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分析化学
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PubMed
高影响因子
TALANTA
·
2018
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IF 4.244
Xiaojuan Liu,Ningning Xu,Panpan Gai,Feng Li
Since melamine is a strong hazard to human health, the development of new methods for highly sensitive detection of melamine is highly desirable. Herein, a novel fluorescent biosensing strategy was designed for sensitive and selective melamine assay based on the recognition ability of abasic (AP) site in triplex towards melamine and signal amplification by Mg 2+ -dependent DNAzyme. In this strategy, the melamine-induced formation of triplex DNA was employed to trigger the strand displacement reaction (SDR). The SDR process converted the specific target recognition into the release and activation of Mg 2+ -dependent DNAzyme, which could catalyze the cleavage of fluorophore/quencher labeled DNA substrate (FQ), resulting in a significantly increased fluorescent signal. Under the optimal conditions, the fluorescent signal has a linear relationship with the logarithm of the melamine concentration in a wide range of 0.005–50 μM. The detection limit was estimated to be 0.9 nM (0.1ppb), which is sufficiently sensitive for practical application. Furthermore, this strategy exhibits high selectivity against other potential interfering substances, and the practical application of this strategy for milk samples reveals that the proposed strategy works well for melamine assay in real samples. Therefore, this strategy presents a new method for the sensitive melamine assay and holds great promise for sensing applications in the environment and the food safety field.
研究领域:
生物化学
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食品安全
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分析化学
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DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
·
IF 2.931
Ruidi Shen,Li Zou,Shixin Wu,Tingting Li,Jing Wang,Jianmin Liu,Liansheng Ling
A novel label-free fluorescent sensor for histidine was developed based upon Cu 2+ -specific DNAzyme, hybridization chain reaction(HCR) and triplex DNA . Cu 2+ can bind to the histidine, in the presence of histidine, leading to the inhibition of the cleavage of substrate strand of Cu 2+ -dependent DNAzyme, then the intact substrate strand trigger the HCR between H1 and H2. The HCR product can be recognized by triplex-forming oligonucleotide (TFO) through triplex formation and reported by the fluorescence of berberine , the fluorescence intensity of the sensing system was proportional to the concentration of histidine during the range of 5.7–455 nmol L −1 , with a detection limit of 2.0 nmol L −1 .
研究领域:
生物化学
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分析化学
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DOI
PubMed
高影响因子
ACS Sensors
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2019
·
IF 6.944
Yaying Huang,Cuiying Lin,Fang Luo,Bin Qiu,Longhua Guo,Zhenyu Lin,Guonan Chen
Lead ions (Pb2+) cause harm to human health. Therefore, the development of fast, effective, and convenient sensors for Pb2+ monitoring has received great attention. In this study, a portable method has been proposed for Pb2+ detection using normal electronic balance as a readout. Magnetic bead-catalytic strand is hybridized with platinum nanoparticles (Pt NPs) functioned substrate strand (Pt-Sub) to form double-stranded DNA first. In the presence of Pb2+, the DNAzyme is activated and cleaved at the ribo-adenosine site of the substrate strand and hence causes Pt NPs to be released into the supernatant, which can be easily separated from the Pt-Sub by a magnet. The separated Pt NPs can effectively catalyze the decomposition of H2O2 to produce O2. In a sealed bottle, the pressure inside the bottle is increased by the generation of oxygen so that the water is discharged from the drainage device, and the weight of the water can be easily and precisely measured by a normal electronic balance. The weighting water has a linear relationship with the concentration of Pb2+ in the range of 2.5–100 nM and the detection limit of 0.83 nM (S/N = 3). The proposed method has been applied to detect Pb2+ in water with satisfactory results. Because the electronic balance is one of the most commonly used analytical tools for the laboratory, it is very practical and convenient without the need for expensive instruments and complicated data processing.
研究领域:
生物化学
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环境科学
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分析化学
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PubMed
高影响因子
ANALYST
·
2014
·Vol. 139
·期 17
·4315-4321
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IF 3.906
Tao Liu,Xiao Zhang,Wenxin Zhu,Wei Liu,Daohong Zhang,Jianlong Wang
The rapid and sensitive detection of Alicyclobacillus acidoterrestris (AA) has become very important due to the frequent occurrence of fruit juice spoilage by AA. In the present study, using guaiacol, both as the metabolic product of AA related to its concentration and as a green colorimetric substrate of G-quadruplex DNAzyme, a novel G-quadruplex DNAzyme-based colorimetric method for a rapid detection of AA has been developed for the first time. Under optimal conditions, AA has been successfully detected in the concentration range of 102–105 cfu mL−1 with a detection limit of 85 cfu mL−1. The recoveries ranging from 71.8% to 115.7% with relative standard deviation from 1.2% to 6.6% in spiked apple and orange juice samples were obtained. Results demonstrate that the sensitivity and precision of the developed method is comparable with most other analytical methods and is prominently rapid than them. We believe that the work provides a novel and effective approach and is beneficial for monitoring and reducing the risk of AA contaminations during the process of fruit juice production.
研究领域:
食品科学
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分子生物学
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DOI
PubMed
高影响因子
ANALYTICAL LETTERS
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2022
·
IF 2.267
Hongjing Sun,Zheng Liu,Zhihong Li,Xinyue Ma,Zixuan Duan,Chunyan Sun
A simple and label-free fluorescent sensor based upon a specific DNAzyme (8–17 DNAzyme) and thiazole orange (TO) for monitoring Pb2+ in water samples was described. The 8–17 DNAzyme was formed by an enzyme strand (17E) and a partially complementary substrate strand (17DS). Thiazole orange, the DNA intercalator, was nonfluorescent in aqueous solution while it intercalates into the 8–17 DNAzyme with a duplex structure resulting in strong fluorescence. In the presence of Pb2+, the 17E was activated and cleaved the 17DS into two at the ribonucleoside adenosine (rA) position, leading to the disruption of the duplex structure. This Pb2+-induced conformational change led to the quenching of the fluorescence of thiazole orange, thus forming the basis for the label-free biosensor. Under the optimized conditions, the developed protocol exhibited sensitive determination of Pb2+ with a detection limit of 0.73 nM and a linear range from 10 to 150 nM. The label-free fluorescent approach exhibited excellent selectivity, strong selectivity, and satisfactory analysis of a drinking water standard reference material and spiked river and tap water samples. Taking the advantage of the structure-switching 8–17 DNAzyme and the fluorescent intercalator of nucleic acids, this label-free sensor provides a new approach for routine screening of heavy metals based upon the DNAzyme.
研究领域:
分析化学
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环境科学
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生物化学
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 42
·19413-19420
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IF 3.3
Zongqiang Li,Jingjing Li,Xu Wang,Qianru Li,Jingru Zhu,Yuying Yao,Zhiqiang Guo,Yu Wang,Su Liu,Jiadong Huang
Escherichia coli (E. coli) is a common Gram-negative bacterium that is widely distributed in nature and is susceptible to natural and random genetic factors. It is a pathogenic factor for many diseases. Sensitive and specific detection of E. coli is an important means to ensure food safety and prevent foodborne disease outbreaks. Ultrasensitive and specific detection of E. coli is still an urgent problem that needs to be solved. An intuitive and convenient colorimetric assay method with high sensitivity based on a DNAzyme-powered AuNR-DNA walker is proposed here for detection of E. coli. The strategy, dependent on the targeted activation of Mg2+-DNAzyme, starts an efficient DNA walking machine, induces the formation of countless peroxidase-mimicking enzymes, and produces a color change via a chromogenic reaction for visual detection of E. coli. This strategy features several aspects. First, this is the first time that an AuNR-based DNA walker is integrated with a colorimetric assay of E. coli. By combining the DNAzyme-powered AuNR-DNA walker and visual detection via the peroxidase-mimicking enzyme, the detection sensitivity is significantly improved compared to those of previously reported colorimetric-based methods, which provides a paradigm for the development of highly sensitive colorimetric assay methods. Second, an activity-controlled nano-DNAzyme is constructed via target-triggered formation of G-quadruplex DNAzyme to achieve low background and high signal-to-noise detection. In addition, this strategy has the advantages of simple operation, short analysis time, low cost, and easy on-site detection. Therefore, the proposed strategy has the potential for application in the detection of E. coli and related food safety analysis and clinical diagnosis.
研究领域:
生物化学
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分子生物学
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纳米技术
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DOI
高影响因子
TALANTA
·
2024
·
IF 5.6
Na Li,Xian Li,Xiaoe Ming,Jingyuan Chen,Yeyi Chen,Lifen Zhou,Ruirui Yao,Yuqi Yao
Deferasirox (DEF) is an important iron chelator for treatment of iron overload–related diseases. Monitoring DEF concentration in human serum will provide some valuable information for clinical diagnosis and therapy of such diseases. In this study, we developed a peroxidase-mimicking colorimetric sensor for the detection of DEF by simple assembly of a telomeric dimeric G-quadruplex DNAzyme with Cu 2+ . The DNAzyme–catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine in the presence of H 2 O 2 can generate a quantitative colorimetric signal, and the color change can be discerned by the naked eye. Compared with the reaction rate of the monomeric G-quadruplex–Cu 2+ DNAzyme, the reaction rate of the dimeric G-quadruplex–Cu 2+ (G2–Cu 2+ ) DNAzyme is significantly accelerated, and the reaction rate gradually increases and then reaches a plateau with increasing number of TTA spacers. Herein, the G2–Cu 2+ DNAzyme is chosen for the highly sensitive detection of DEF based on the DEF–Cu 2+ complex–induced inhibition of its peroxidase-mimicking activities. The limit of detection (LOD) of DEF is achieved as low as 0.03 μM, and the linear range is from 0.05 to 1.2 μM. The proposed strategy exhibits excellent selectivity in the presence of potential interferents, such as metal ions and small molecules. Importantly, the G2–Cu 2+ DNAzyme is further expanded to detect DEF in dispersible tablets and human serum samples. Overall, this G2–Cu 2+ DNAzyme provides a simple, low-cost, and rapid platform for DEF detection. This novel strategy is the first example of DEF analysis by utilizing signal amplification technology based on the G-quadruplex DNAzyme and holds great potential for DEF quality control and therapeutic drug monitoring.
研究领域:
生物化学
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医学诊断
·
药物分析
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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）