ANALYST
·
2025
·
IF 3.3
Shaoying He,Wei Lin,Xin Liu,Fei Li,Hong Liang,Huo Xu,Chunhua Lu,Chao Xing
Lead pollution presents a significant threat to ecological systems and human health, underscoring the urgent need for highly sensitive detection methods. Herein, we introduce a novel DNA concatemer-encoded CRISPR/Cas12a fluorescence sensor (MDD-Cas12a) for sensitive detection of Pb2+ based on DNAzymes. To accomplish this, we designed a substrate strand containing a long DNA concatemer encoding multiple protospacer adjacent motifs (PAMs) and protospacer sequences for activation of the CRISPR/Cas12a system. The DNA concatemer was subsequently anchored to the surface of magnetic beads (MBs) to fabricate a MBs-DNA concatemer nanoprobe. In the presence of Pb2+, the DNAzyme structure catalyzes the cleavage of the substrate strand, leading to the release of DNA concatemers. Following magnetic separation, the released DNA concatemers significantly activate the non-specific trans-cleavage activity of the Cas12a/crRNA complex. The fluorescence reporter DNA is then completely cleaved by the activated Cas12a/crRNA complex, and the Pb2+ concentration in the sample can be quantified by measuring the fluorescence signal. By harnessing the specific recognition capability of DNAzymes for Pb2+, the programmability of DNA concatemers, and the self-amplification features of the CRISPR/Cas12a system, the MDD-Cas12a platform demonstrates high sensitivity and specificity for detecting Pb2+ in milk and lake water samples.
研究领域:
生物化学
·
分子生物学
·
环境科学
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DOI
PubMed
高影响因子
TALANTA
·
2013
·
IF 3.498
Yuezhen He,Xiaoxun Wang,Yuzhong Zhang,Feng Gao,Yongxin Li,Hongqi Chen,Lun Wang
In this work, we reported a sensitive chemiluminescent immunosensor for the detection of human leptin by using hemin/G-quadruplex DNAzymes to amplify detection signal. In this sensing system, the primary antibody (anti-human leptin) was firstly bound to the 96-well plates, and human leptin and biotinylated secondary antibody were successively combined to form sandwich-type immune complex through specific interactions. Then streptavidin labeled with hemin/G-quadruplex DNAzymes was assembled to the sandwich-type immunocomplex by streptavidin–biotin interaction. The DNAzymes exhibited an excellent catalytic activity to the chemiluminescent reaction of luminol with hydrogen peroxide in strong alkaline solution, leading to significant enhancement in response signal. Under the optimum conditions, the proposed immunosensor showed high sensitivity and selectivity with a low detection limit of 1.9 pg mL −1 and a wide linear response range of human leptin from 10 to 1000 pg mL −1 . The immunosensor was used to detect human leptin in serum, and the results were in good agreement with the data obtained by conventional ELISA method.
研究领域:
生物化学
·
医学检测
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Xiaolun Peng,Jiaxin Zheng,Ting Bao,Wei Wen,Xiuhua Zhang,Shengfu Wang
A novel dual-amplified electrochemical biosensor based on Exonuclease III (Exo III) and Cu(II)-dependent DNAzymes (Cu 2+ -DNAzymes) was developed for ultrasensitive electrochemical evaluation of pyrophosphatase (PPase) activity with the help of one-step synthesis of BSA-directed gold nanoclusters-manganese dioxide (AuNCs-MnO 2 ) nanoflakes with peroxidase-like characteristics as a catalytic platform. For biosensor preparation, under the catalytic hydrolysis of the PPase, copper ion (Cu 2+ ) was released from the Cu 2+ -coordinated pyrophosphate ions (Cu 2+ –PPi) complex which was formed by the coordination reaction of copper ion (Cu 2+ ) and pyrophosphate ions (PPi). The released Cu 2+ , acting as an indispensable cofactor, could activate Cu 2+ -DNAzymes to turn on the amplification process and then generated the single-stranded product (S1) that hybridized to the hairpin-type capture probe (HP1). Subsequently, the addition of Exonuclease III (Exo III) enabled the reuse of S1 and produced the final cleavage fragment, which closely linked the functionalized AuNCs-MnO 2 nanoflakes to the electrode surface. The superior peroxidase-like characteristics of nanoflakes provided stable catalytic signal output and realized electrochemical monitoring of PPase activity with a detection limit of 0.0058 mU/mL. Importantly, the biosensor also had a good performance in inhibitors screening of target PPase. The use of AuNCs-MnO 2 nanoflakes instead of natural enzymes combined with DNAzymes amplification strategy offered more possibilities for the detection of various biomolecules.
研究领域:
生物化学
·
纳米技术
·
分析化学
·
生物医学工程
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DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Ying Zhang,Wang Ren,Hong Qun Luo,Nian Bing Li
A new magnetic bead-based cascade amplification strategy for highly sensitive visual detection of proteins (thrombin as a model analyte) was developed by coupling target-triggered hybridization chain reaction (HCR) with the synergistic catalysis of DNA concatemer-mediated hemin/G-quadruplex DNAzymes and Pt nanozymes. Initially, the biotinylated primer DNA (P-DNA) was complementary with aptamer to form dsDNA which was further linked to streptavidin-coated magnetic bead (MB), thereby fabricating the expected MB-based aptasensor . In the presence of target TB, the aptamer was taken away from the aptasensor, and the free P-DNA immediately triggered HCR to spontaneously form DNA concatemer-directed nanochains with numerous DNAzymes and Pt nanoclusters (PtNCs) to achieve cascades signal amplification . The dual peroxidase mimetics catalyzed the H 2 O 2 -mediated oxidation of colorless 3,3′,5,5′-tetramethylbenzidine (TMB) into the colored TMB oxides (oxTMB), causing intensified color change of the chromogenic solution for the highly sensitive naked-eye detection of as low as 100.0 pM TB. In this strategy, the employment of magnetic separation and exonuclease III (Exo III)-assisted digestion of residual dsDNA minimized the background noise and avoided the false positive results, greatly improving the detection accuracy and sensitivity with a low limit of detection (LOD=15.0 pM). The proposed visual platform has promise for detecting various types of proteins with careful DNA sequence designs.
研究领域:
生物化学
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纳米技术
·
分析化学
·
生物传感器
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DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Wenjiao Zhou,Xue Gong,Yun Xiang,Ruo Yuan,Yaqin Chai
Visual detections have attracted great research attentions recently due to their convenient monitoring of the target analytes without using any advanced instruments. However, achieving visual detection of trace amounts of biomolecules with PCR-like sensitivity remains a major challenge. In current work, we describe a new quadratic signal amplification strategy for sensitive visual detection of HIV DNA biomarkers based on exonuclease III (Exo III)-assisted DNA recycling amplification and DNAzymes. The presence of the target HIV DNA leads to two independent and simultaneous DNA recycling processes to achieve quadratic signal amplification with the assistance of Exo III. This quadratic signal amplification results in catalytic cleavage of the G-quadruplex sequence-locked hairpin probes to release numerous active G-quadruplex sequences, which further associate with hemin to form DNAzymes and cause significantly intensified color change for sensitive and visual detection of HIV DNA down to 2.5 pM. The proposed visual detection method employs un-modified hairpin DNA as probes, avoids using any complex and expensive instruments for signal transduction and is essentially simple. This method also shows single-base mismatch discrimination capability as well. All these features make our developed DNA detection method holds great potential for visual monitoring of various DNA biomarkers at ultralow levels with careful and proper probe designs.
研究领域:
分子生物学
·
分析化学
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PubMed
高影响因子
Catalysts
·
2022
·Vol. 13
·期 1
·81
·
IF 4.501
Ying Zhang,Junya Liao,Hao Liang
DNA-based biomimetic enzymes have attracted extensive attention due to their unique structure and stability compared to natural enzymes. Meanwhile, the specific sequences of DNA itself also have a catalytic effect. Herein, we first designed three guanine-rich DNA sequences numbered c−Myc3c, PG4TC, and TTT to construct g−quadruplex/hemin DNAzymes. Then, the g−quadruplex/hemin DNAzymes with the best activity were selected by a comprehensive examination of activity, degradation rate, and affinity. Subsequently, the stability and reusability of UiO66−DNAzymes were investigated using UiO66 as the carrier to immobilize DNAzymes. The results showed that UiO66−DNAzymes had excellent reusability and stability. Finally, UiO66−DNAzymes were successfully used for glucose detection by cascading with glucose oxidase (GOx) with a detection limit of 0.62 μM. The constructed glucose sensor had a good specificity, which is of great significance for developing a novel, accurate, fast, and economical glucose detection sensor.Keywords:metal-organic frameworks;DNAzymes;enzyme immobilization;biomimetic enzymes;glucose detection
研究领域:
生物化学
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纳米技术
·
分析化学
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DOI
高影响因子
Chemistry-Switzerland
·
2023
·Vol. 5
·期 3
·1497-1507
·
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
·
催化
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2012
·
IF 4.555
Ruimin Li,Cen Xiong,Zhiyou Xiao,Liansheng Ling
A novel colorimetric method for detection of cholesterol was developed with hemin-G-quadruplex DNAzyme by transducing oxidation of cholesterol into the color change of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS 2− ). Oligonucleotide 5′-GTGGGTAGGGCGGGTTGG-3′ (Oligo-1) formed G-quadruplex structure in the presence of K + , it acted as a horseradish peroxidase (HRP) mimicking DNAzyme when binding hemin and catalyzed the oxidation of colorless ABTS 2− to green ABTS − by H 2 O 2 , which was produced by the reaction of cholesterol and oxygen that catalyzed by cholesterol oxidase. Therefore, the oxidation of cholesterol could be transduced into the color change of ABTS 2− by combining these two reactions. Under the optimum conditions, the absorbance was proportional to the concentration of cholesterol over the range of 1.0–30 μM, with a linear regression equation of A = 0.362 + 0.0256 C ( C : μM, R = 0.998) and a detection limit of 0.10 μM (3 σ /slope). Moreover, the practicability of the assay in the detection of cholesterol in human serum was studied as well.
研究领域:
生物化学
·
医学诊断
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DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2021
·
IF 15.419
Ruo-Can Qian,Ze-Rui Zhou,Weijie Guo,Yuting Wu,Zhenglin Yang,Yi Lu
Regulating cell–cell interactions and cell behaviors via cell surface engineering is of significance for biological research such as cell fate control and cell therapy. While extensive efforts have been made to induce cell–cell assembly via various cell surface modifications triggered by macromolecules or organic metabolites, controllable cell–cell interactions that include both assembly and disassembly triggered by metal ions remain a challenge. Herein, we report a strategy based on DNAzymes to realize controllable cell–cell interactions, triggered by metal ions. The metal-dependent DNAzyme-based cleavage can effectively manipulate cell behaviors, including cell–cell conjunctions and disaggregation. Using a Zn2+-specific DNAzyme, a Mg2+-specific DNAzyme, and their respective substrate strands as the building blocks, the corresponding DNA double-chain switches enabling two-factor disassembly are demonstrated. Moreover, the method has been applied to control the assembly and disassembly between two cell spheroids. Since a wide variety of metal-specific DNAzymes are available, this method can be readily applied to construct cell dynamic systems controlled by other metal ions, providing a smart and versatile platform to regulate dynamic cell behavior.
研究领域:
生物研究
·
细胞治疗
·
分子工程
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DOI
PubMed
高影响因子
Chemical Science
·
2020
·Vol. 11
·期 33
·8966-8972
·
IF 9.346
Xia Li,Fang Yang,Wenjiao Zhou,Ruo Yuan,Yun Xiang
DNAzymes exhibit high potential as gene silencing agents for therapeutic applications. Such purposes, however, are significantly challenged by the targeted and successful delivery of unmodified DNAzymes into cells with minimal side effects. Here, we set out to formulate and demonstrate a new stimuli-responsive and constrained aptamer/DNAzyme (Apt/Dz) catenane nanostructure for highly specific gene silencing. The rational design of the Apt/Dz catenane nanostructure with the respective integration of the aptamer sequence and the completely closed catenane format enables both the targeted capability and significantly improved nuclease resistance, facilitating the stable and targeted delivery of unmodified Dz into cancer cells. Moreover, the Dz enzymatic activity in the constrained structure can only be conditionally regulated by the specific intracellular mRNA sequences to silence the target gene with highly reduced side effects. Results show that the Apt/Dz catenane nanostructure can effectively inhibit the expression of the target gene and the proliferation of cancer cells with high specificity.
研究领域:
分子生物学
·
治疗学
·
纳米技术
·
癌症研究
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2014
·Vol. 299
·期 3
·1911-1919
·
IF 1.415
Ma Dandan,Yuan Yali,Xiao Xilin,Gao Yangyang,Li Yuhui,Xu Wenhui,Long Wei
A novel and highly sensitive electrochemical DNAzymes biosensor was fabricated using Au nanoparticles (AuNPs) immobilized on the surface of Au electrode that had been previously modified with self-assembled monolayers of 1,6-hexanedithiol. Different modified electrodes were prepared and characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The AuNPs were found to have a large surface area to anchor a large number of negatively charged phosphate backbones of DNAzymes, which further absorbed the electroactive indicator of hexaammineruthenium(III) ([Ru(NH 3 ) 6 ] 3+ ) to amplify the electrochemical signal. In the presence of target molecules, a large amount of DNA partly associated with [Ru(NH 3 ) 6 ] 3+ were removed from the electrode surface, leading to a significant decrease in peak current. Differential pulse voltammetry signals of [Ru(NH 3 ) 6 ] 3+ provided quantitative measures of the concentrations of uranyl ion (UO 2
2+ ), with linear calibration ranging from 13 pM to 0.15 nM and a detection limit of 5 pM. The presence of other metal ions did not affect the detection of UO 2
2+ , which indicated the high specificity of UO 2
2+ . Therefore, a new electrochemical DNAzymes sensor was designed with specific DNAzymes and AuNPs as immobilization platform and signal amplifier.
研究领域:
分析化学
·
环境科学
·
纳米技术
·
生物化学
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DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 37
·13160-13166
·
IF 4.174
Yali Yu,Qingqing Zhang,Heng Gao,Chenxiao Yan,Xiong Zheng,Tong Yang,Xiaoshun Zhou,Yong Shao
G-quadruplex DNAs (G4s) have been reported to exhibit the DNAzyme activities by binding with some metal complexes and functional organic ligands. However, there is a challenge to develop metalloenzyme-mimic G4-based innate DNAzymes using the complexed metal ions directly serving as the active centers. This will diversify DNAzymes for developing novel devices since G4 structures are more polymorphic than the other DNA foldings. In this work, we found that the lanthanide trivalent cerium ion of Ce3+ can bind to the human telomere G4 (htG4) according to a 1 : 2 binding mode favorable for creating metalloenzymes-mimic G4 DNAzymes. This Ce3+-G4 entity exhibits a peroxidase activity towards the oxidation of the substrate of 3,3,5,5-tetramethylbenzidine (TMB) by hydrogen peroxide. The 5′ G4 tetrads with the orderly arranged carbonyl oxygen atoms are believed to be the coordination sites for Ce3+ and favor the conversion between Ce3+ and Ce4+. Our work provides an alternative feasibility in developing the G4-based innate DNAzymes for variant applications.
研究领域:
生物化学
·
分子生物学
·
催化
·
核酸化学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）