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
·
医学诊断
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Ting Hou,Ningning Xu,Wenxiao Wang,Lei Ge,Feng Li
In conventional photoelectrochemical (PEC) analysis, photoactive materials are usually immobilized on electrode surfaces, and such immobilization procedures are tedious and time-consuming, and it is also difficult to prepare electrodes with good reproducibility. To circumvent such limitations, we propose here a truly immobilization-free diffusivity-mediated PEC bionsensing strategy for microRNA assay, using methylene blue (MB) in solution as the photoactive probe, and nonmodified indium tin oxide (ITO) glass as the working electrode. The hybridization between the target microRNA and the MB-labeled single-stranded DNA probe (MB-DNA) triggers the digestion of MB-DNA by T7 exonuclease (T7 Exo), thus to generate MB-labeled mononucleotide, and then the released target microRNA initiates the subsequent cycling processes and generates a large amount of MB-labeled mononucleotides. Due to the diffusivity difference between MB-DNAs and MB-labeled mononucleotides, significantly increased photocurrent signal is observed for MB-labeled mononucleotides as compared to that of MB-DNAs. Therefore, via this “signal-on” mode and the T7 Exo facilitated signal amplification, a facile and highly sensitive immobilization-free PEC microRNA assay is readily realized, with a detection limit down to 27 aM. Moreover, this strategy exhibits excellent specificity and is successfully applied in detecting microRNA spiked in serum samples. Since all the reactions take place in homogeneous solutions and no electrode modification is needed, this PEC biosensing strategy exhibits the advantages of simplicity, rapidness, and good reproducibility. More significantly, it provides a novel concept to design truly immobilization-free PEC biosensing systems, and shows potential to be applied in bioanalysis and biochemical research.
研究领域:
生物分析
·
分子生物学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Xiuzhong Wang,Shanshan Dong,Panpan Gai,Rui Duan,Feng Li
The ubiquitous presence of antibiotic residues in foodstuff have serious health consequences for consumers from allergic reactions to the evolution of antibiotic-resistant bacteria. To address this problem, a novel homogeneous electrochemical aptasensor with high sensitivity and specificity is designed for antibiotic residues detection based on target-induced and T7 exonuclease-assisted dual recycling signal amplification strategy. It was realized by the remarkable diffusivity difference between hairpin probe and the mononucleotides towards the negatively charged indium tin oxide electrode. For the proof-of-concept experiment, ampicillin , was employed as a model analyte to examine the desirable properties of this assay. A low detection limit of 4.0 pM toward ampicillin with an excellent selectivity could be achieved, which has been successfully applied to assay antibiotic in milk. What's more, compared with the immobilization-based electrochemical means, the proposed sensing system avoids the tedious and time-consuming steps of electrode modification, making the experimental processes much simpler and more convenient. With the advantages of high sensitivity, excellent selectivity and simple operation, it is believed that this strategy possesses great potential for the simple, easy and convenient detection of antibiotic residues in food safety field.
研究领域:
食品安全检测
·
生物传感技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2014
·
IF 5.825
Mo Wang,Zhengliang Fu,Bingchen Li,Yunlei Zhou,Huanshun Yin,Shiyun Ai
Taking advantage of the special exodeoxyribonuclease activity of T7 exonuclease, a simple, sensitive, selective, and label-free microRNA biosensor based on the cyclic enzymatic amplification method (CEAM) has been proposed. First, thiol functionalized DNA probes were assembled onto a gold nanoparticles modified gold electrode surface through a Au–S bond, followed by hybridizing with target miRNA. Subsequently, DNA in RNA/DNA duplexes was digested by T7 exonuclease, which can release the microRNA molecules from the electrode surface and return into the buffer solution. Meanwhile, the released microRNA can further hybridize with the unhybridized DNA probes on the modified electrode surface. On the basis of it, an isothermal amplification cycle is realized. The T7 exonuclease-assisted CEAM achieved a low detection limit of 0.17 fM. Moreover, this assay presents excellent specificity with discriminating only a single-base mismatched microRNA sequence. Furthermore, this work can also be applied to detect avian leukemia based on the decreased expression level of microRNA-21.
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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癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Wenqi Zhang,Jiang Ling,Di Wen,Zijia Cheng,Suiping Wang,Yanjun Ding
The early diagnosis of acute myocardial infarction (AMI) was a tough nut in both clinical medicine and forensic science since the occurrence of gross changes needed at least 12 h. Compared to other diagnostic methods, microRNA was reported as an earlier cardiac biomarker with higher sensitive. In this work, we designed a novel fluorescent analytical strategy using a dual-emission probe based on T7 Exo-assisted target recycling amplification for simultaneous detection of AMI-related miR-199a and miR-499, which could indicate myocardial ischemia or damage in AMI. The dual-emission probe was conducted by yellow-emission and red-emission CdTe quantum dots capped with beta-cyclodextrin. The florescence of probe was firstly quenched by graphene oxide (GO) and then recovered in the presence of target miR-199a and miR-499. Under the optimized conditions, the limit of detection as low as 0.1 pM was obtained and the overall test could be performed within 50 min. Besides, the simultaneous detections of microRNAs in spiked serum samples were achieved with the recovery of 81.3–109.6%, which suggested the potential method for diagnosis in practical. The advantages of this method include easy operation, high accuracy and low labor cost, which makes point-of-care test possible both in hospital and forensic application.
研究领域:
临床医学
·
法医学
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生物技术
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纳米技术
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 23
·11262-11269
·
IF 6.97
Zhichao Chen,Yiming Xie,Wan Huang,Chuanying Qin,Aimin Yu,Guosong Lai
As an important biomarker for early disease diagnosis, microRNA-21 (miRNA-21) has attracted considerable attention owing to its accurate detection. Herein we combine the one-step biorecognition reaction at a vertically aligned nanostructure-based biosensor with the T7 exonuclease (Exo)-assisted target recycling to develop a novel electrochemical bioassay method for miRNA-21 detection. The vertically aligned nanointerface is constructed through the covalent attachment of terminally carboxylated single-walled carbon nanotubes (SWCNTs) at an aryldiazonium salt-modified electrode, which enables the noncovalent adsorption of a ferrocene-labeled single-stranded signal DNA to obtain the biosensor. Upon its incubation with a target miRNA-21 solution, DNA/RNA hybridized duplexes will form and release from the electrode surface, leading to the corresponding electrochemical signal decrease of the biosensor. Moreover, this biorecognition reaction can also trigger the T7 Exo-assisted target recycling to achieve great signal amplification. Together with the highly efficient biorecognition and excellent electron transfer promotion at the vertically aligned SWCNTs, this biosensor exhibits a wide linear range varying from 0.01 to 100 pM and a low detection limit down to 3.5 fM. Considering its obvious performance superiority and convenient manipulations, this vertically aligned SWCNT-based electrochemical biosensing method has extensive potential for practical applications.
研究领域:
生物化学
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纳米技术
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电化学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Jia Ge,Xin-Geng,Ya-Hui Du,Jia-Jia Chen,Lin Zhang,Dong-Mei Bai,Dan-Yang Ji,Ya-Lei Hu,Zhao-Hui Li
In this work, a simple and signal-on assay has been developed for highly sensitive and selective detection of mercury ion (Hg 2+ ) based on the WS 2 nanosheets and T7 exonuclease-assisted cyclic signal amplification. WS 2 nanosheet exhibits differential affinity toward short oligonucleotide fragment versus single-stranded DNA (ssDNA) probe, which is used as an adsorption material for capturing ssDNA and an efficient fluorescence quencher for reducing the background signal. T7 exonuclease, a sequence independent nuclease, catalyzes the removal of 5′ mononucleotides from the 5′ termini of double stranded DNA, while its activity on ssDNA is limited. Without Hg 2+ , FAM-labelled ssDNA probe and target probe are adsorbed by the WS 2 nanosheet and the fluorescence of FAM-labelled signal probe is quenched. In the presence of Hg 2+ , a FAM-labelled ssDNA probe could hybridize with the target probe to form duplex structures with a blunt 5′-terminal of signal probe through the formation of T-Hg 2+ -T base pairing. The FAM-labelled signal probe with a blunt 5′-terminal in the formed duplex can be digested by T7 exonuclease in the direction from 5′ to 3′, liberating the FAM fluorophore and releasing the Hg 2+ . The released target Hg 2+ and the remaining probe then bind another FAM-labelled ssDNA, and initiate the next round of cleavage, resulting in the release of numerous FAM labels back into the solution and significantly amplified fluorescent signal. This approach can warrant the detection limit for Hg 2+ down to 0.1 nM (S/N = 3) with high selectivity against other metal ions. Moreover, the application of the sensor for lake water shows that the proposed method works well for real samples. This research demonstrates an alternative approach to detect targets of interest that holds high prospects for detecting other biomolecules or metal ions in the near future.
研究领域:
分析化学
·
环境科学
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纳米技术
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Yang-Yang Hou,Wan-Zhen Xie,Xuecai Tan,Ke-Jing Huang,Jing Xu
A highly sensitivity self-powered biosensor is developed based on T7 exonuclease (T7 Exo) and 3D DNA walker induced rolling circle amplification (RCA) for electrochemical/colorimetric dual-mode detection of microRNA-21 (miRNA-21) with improved reliability. Taking its advantage of fascinating properties, such as high structure defects and good conductivity , graphdiyne is prepared and used to prepare high-performance enzyme biofuel cell. T7 Exo-assisted 3D DNA walker target recognition triggers RCA reaction to obtain a significantly amplified signal response. A capacitor is integrated to the enzyme biofuel cell to further amplify the electrochemical output signal of the self-powered biosensor. In detection system, glucose oxidase catalyzes glucose oxidation to produce hydrogen peroxide, and 3,3′,5,5′-tetramethylbenzidine (TMB) is then catalyzed to generate colored products, so as to achieve the colorimetric detection of the target. Analysis signals of diverse modes are recorded independently. Consequently, detection of microRNA with improved reliability and wider signal response range are achieved by electrochemical/colorimetric dual-mode with detection limits of 0.15 and 33 fM ( S/N = 3) respectively. In addition, the proposed self-powered biosensor successfully applied for the detection of miRNA-21 in human serum samples, confirming its practical applicability in clinical diagnosis. It is powerfully anticipated the proposed self-powered biosensor possesses great potential to be applied to other biomedical domains.
研究领域:
生物化学
·
分子生物学
·
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Jia Tang,Yuxin Xing,Zhenqiang Wang,Mengnan Yang,Jixi Zhang,Kaiyong Cai
The design and interfacial engineering of DNA functionalized nanosensors with spatially separated but functionally integrated detection units holds a great promise in optical biosensors. In this study, we developed a bi-component hybrid of Janus nanoquencher particles with immobilized enzymes for fluorescence-based “off-on” detection in solution. Specifically, the hybrids consisting of a mesoporous polydopamine nanoparticle (MPDA) side (∼200 nm) asymmetrically attached with a gold (Au) particle side (∼30 nm) were generated through electrostatic repulsion-controlled growth. By regioselective binding and modification of the exposed side of the particles, fluorescent DNA probes and duplex-specific nuclease (DSN)/T7 exonuclease (T7) were subcompartmentalized on the MPDA and Au side, respectively, to realize substrate recognition and target recycling via the formation and hydrolysis of DNA hybrids. By using microRNAs (miRNAs) as a model target, the developed nanosensor realized a sensitive detection with a low limit of 32 fM (in a linear range from 20 fM–500 fM). Additionally, a high selectivity capable of discriminating a single-base mismatch, as well as a long-term detection stability were realized by the asymmetric interface designs and enzyme immobilization. The methodology is promising in the design and development of DNA probe-loaded hybrid nanosensors.
研究领域:
生物传感器
·
纳米技术
·
分子生物学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）