SENSORS AND ACTUATORS B-CHEMICAL
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2017
·
IF 5.401
Lili Yu,Wei Lan,Hui Xu,Hou Chen,Liangjiu Bai,Wenxiang Wang
We constructed a fluorometric and sensitive analysis of mercury (II) based on toehold-mediated strand displacement reaction, exonuclease III (Exo III) assisted target recycling, hybridization chain reaction (HCR), fluorescence intercalator SYBR Green I (SG) and grapheme oxide (GO). Firstly, toehold-mediated strand displacement reaction was constructed by using thymine-Hg 2+ -thymine (T-Hg 2+ -T) recognition mechanism between the helper hairpin DNA and assisted DNA. And then, the Exo III disintegrated the double-stranded DNA (dsDNA) by catalyzing the gradual removal of mononucleotides from 3′-hydroxyl terminus of dsDNA with a blunt 3′ terminus. It resulted in the target and assisted DNA recycling and released a trigger strand DNA at the same time. Finally, the trigger strand DNA initiated the hybridization chain reaction (HCR), forming long double helices, which achieved a secondary amplification due to the continuous target recycling, trigger strand DNA release and HCR. The number of T-T mismatches, the concentration of SG, Exo III and GO, the incubation time of Exo III were all optimized. Under the optimized condition, the limit of detection for Hg 2+ can be down to 7.37 pM with a linear range from 0 to 1.5 nM. This sensor exhibits high selectivity against other metal ions, and it works well for real samples.
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BIOSENSORS & BIOELECTRONICS
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2015
·
IF 6.409
Hong Guo Chen,Wang Ren,Jing Jia,Ji Feng,Zhong Feng Gao,Nian Bing Li,Hong Qun Luo
We describe here a fluorometric assay for sensitive detection of oligonucleotides , based on a target recycling amplification strategy driven by toehold-mediated strand displacement reaction and on exonuclease III (Exo Ш)-assisted fluorescence background suppression strategy. The network consists of a pair of partially complementary DNA hairpins (HP 1 and HP 2 ) with 3′ overhang ends, between which the spontaneous hybridization is kinetically hindered by the stems. The target DNA is repeatedly used to trigger a recycling progress between the hairpins, generating numerous HP 1 –HP 2 duplex complexes. Exo III was then employed to digest the double strand parts of the residual hairpins and the intermediate products. The fluorescent dye , SYBR Green I , binds to the double-strand DNA products and emits strong fluorescence to achieve sensitive detection of the target DNA with the detection limit of 5.34 pM. Moreover, this proposed strategy showed high discrimination efficiency towards target DNA against mismatched DNA and was successfully applied in the analysis of human serum sample.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Yufei Liu,Suyu Meng,Jingjing Qin,Ruiying Zhang,Ningning He,Yaoyao Jiang,Hong Chen,Na Li,Ying Zhao
As a toxic substance on human health produced in food thermal treatment, simple analytical approaches are highly desired for the detection of acrylamide (ACR) in foods. With the aid of exonuclease III (Exo III), a simple fluorescence sensor was proposed based on carboxyfluorescein-labeled double-stranded DNA (FAM-dsDNA) and a cationic conjugated polymer (PFP). Fluorescence resonance energy transfer (FRET) efficiency between FAM and PFP was changed with and without ACR. When ACR was present, ACR and single-stranded DNA (P1, ssDNA) formed an adduct, allowing free FAM-labeled complementarity strand DNA (P2, FAM-csDNA) to appear in the solution and avoiding the digestion of P2 by Exo III. After the addition of PFP, the interaction of PFP and FAM induced strong FRET. Under optimized conditions, ACR was detected with a limit of detection (LOD) of 0.16 μM. According to this biosensor, a LOD of 1.3 μM in water extract samples was observed with a good recovery rate (95–110 %).
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Journal of Pharmaceutical Analysis
·
2025
·
IF 8.9
Shiquan Zheng,Jiale Ke,Hanren Chen,Huaze Shao,Fengxin Zheng,Runhui Zhang,Zean Zhao,Jianxin Pang,Lihong Liu
The lack of a cell-based screening method limits urate-lowering drug development. A novel method combining aptamer sensor array (ASA), exonuclease III (Exo III)- powered 3D DNA walker (DW), and linear discriminant analysis (LDA) was developed for detecting uric acid (UA) in cell lysates, referred to as ASA–Exo III-DW–LDA. Three aptamers (Apts) with different affinities for UA and its structurally similar compound, xanthine (Xan), were used to design the ASA. The combination of ASA and Exo III-DW enabled the detection of UA at the picomolar level, whereas LDA was employed to differentiate UA signals from the mixed signals of UA and Xan. Significantly, Pearson correlation analysis revealed a strong correlation between our method and the 14 C radioactive labeling method for urate anion exchanger 1 (URAT1) inhibitors, with r = 0.9880 for lesinurad and r = 0.9777 for benzbromarone. Using our method, kaempferol was identified as a promising hit compound for inhibiting the URAT1, because of its low half-maximal inhibitory concentration (IC 50 ) (18.96 μM) low toxicity in mouse renal tubular epithelial cells (mTECs), and significant urate-lowering effect in hyperuricemic mice at 5 mg/kg. Overall, this method is sensitive, cost-effective and safe, offering a novel strategy for routine urate-lowering drug screening in standard laboratories.
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ACS Sensors
·
2020
·
IF 7.333
Xiao-Bin Huang,Shao-Hua Wu,Hao-Cheng Hu,Jian-Jun Sun
The “turn-on” mode surface-enhanced Raman scattering (SERS) aptasensor for ultrasensitive ochratoxin A (OTA) detection was developed based on the SERS “hot spots” of AuNanostar@4-MBA@Au core–shell nanostructures (AuNS@4-MBA@Au) and exonuclease III (Exo III)-assisted target cycle amplification strategy. Compared with conventional gold nanoparticles, AuNS@4-MBA@Au provides a much higher SERS enhancement factor because AuNS exhibits a larger surface roughness and the lightning rod effect, as well as an excellent electromagnetic field between the AuNS core and the Au shell, which contribute to the superstrong SERS signal. Meanwhile, Exo III-assisted target cycle amplification can be used as an effective method for the further amplified detection of OTA. Additionally, the utilization of streptavidin magnesphere paramagnetic particles offers a green, economical, and facile technology for the accumulation and separation of the signal probe AuNS@4-MBA@Au from solution. All these factors lead to a significant enhancement of detectable signals and superhigh sensitivity. As a result, the limit of detection as low as 0.25 fg mL–1 could be achieved, which was lower than that in the other reported literatures on SERS methods for OTA detection as we know. The developed SERS aptasensor also provides a promising tool for foodstuff detection.
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NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 6
·4714-4718
·
IF 3.201
Yu Ling,Xiao Fang Zhang,Xiao Hui Chen,Li Liu,Xiao Hu Wang,De Shou Wang,Nian Bing Li,Hong Qun Luo
Sensitive detection of disease-related DNA is of great significance for early and accurate diagnosis and therapy. To achieve this aim, we constructed a dual-cycling amplification biosensor for target oligonucleotide detection. Based on the toehold-mediated strand displacement reaction (TSDR), target DNA competitively hybridized with the assistant DNA which previously formed a duplex complex with the trigger DNA, and the trigger DNA was released. Exonuclease III (Exo III) would specially hydrolyze the assistant DNA in the new duplex DNA to free the target DNA for a new cycle. Similarly, based on the TSDR and Exo III assisted amplification, the released trigger DNA would repeatedly open the G-quadruplex hairpins and promote the generation of numerous G-quadruplex sequences. Then, the fluorescence intensity of Thioflavin T (ThT) would present apparent enhancement due to the formation of the G-quadruplex/ThT complex. The commercially available ThT is economical and of low toxicity. More importantly, owing to its satisfactory water solubility, ThT effectively avoids the introduction of organic solvents. There was no need for expensive modification through the whole process. The proposed method displayed high distinction efficiency towards target DNA against mismatched DNA. Additionally, the linear range of this strategy was 0.2–10 nM, and the detection limit was 0.04 nM. Besides, this sensor can be applied in human serum with satisfactory results.
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FOOD CONTROL
·
2018
·
IF 3.667
Xueqi Leng,Yuqin Tu,Yunping Wu,Yu Wang,Su Liu,Qianqian Pei,Xuejun Cui,Jiadong Huang
A fluorescence sensing strategy was described for the determination of melamine with ultrasensitivity and high specificity. This strategy relies on the combination of proximity ligation assay (PLA)-modulated thymine–melamine–thymine (T–melamine–T) triplex structure along with exonuclease III (Exo III)-aided recycling amplification. The reaction system involves three DNA probes (poly A, tDNA and molecular beacon (MB)). Probe ploy A is an adenine enriched sequence containing an apurinic/apyrimidinic site (AP site). It can provide a hydrophobic vacancy for specially recognizing melamine to bind the nucleobase through pseudo-base pairing and participate in PLA modulated T-melamine-T triplex structure. Probe tDNA can form T-melamine-T with probe poly A via PLA only in the presence of melamine. Probe MB is modified with a fluorophore at its 5′-terminus and a quencher at an internal position, which can self-hybridize to form a hairpin structure, positioning the fluorophore in close proximity to the quencher. Therefore, the binding of MB did not yield any fluorescence signal. However, in the presence of melamine, a T-melamine-T triplex structure is formed through PLA. Probe MB can hybridize with t T-melamine-T triplex structure to yield a substrate for interaction with Exo III. As a result, the T-melamine-T triplex structure is released. Next, the released T-melamine-T triplex structure will hybridize with another MB probe to achieve the Exo III-aided recycle amplification. This is the first example of PLA-modulated T-melamine-T triplex structure coupled with Exo III-aided recycling amplification. Under optimal conditions, the assay has a detection range over 4 orders of magnitude and a limit of detection of 4.4 nM. Moreover, the assay is rapid, simple and inexpensive. Hence, the strategy may open new avenues for ultrasensitive and highly specific detection of melamine encounted in food analysis .
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MICROCHIMICA ACTA
·
2017
·Vol. 185
·期 1
·1-7
·
IF 4.58
Hong Minqiang,Zeng Bihua,Li Mingyu,Xu Xueqin,Chen Guonan
An ultrasensitive conformation-dependent colorimetric assay has been developed for the detection of mercury(II) ions. It is based on the use of exonuclease III (Exo III)-assisted target recycling and gold nanoparticles (AuNPs). In the absence of Hg(II), the hairpin-shaped DNA probe (H-DNA) binds to AuNPs and stabilizes them in solutions of high ionic strength. In the presence of Hg(II), on the other hand, the sticky termini of the H-DNA form a rigid DNA duplex stem with a blunt 3′-terminus. Thus, Exo III is activated as a biocatalyst for selective and stepwise removal of mononucleotides from the 3′-terminus of the H-DNA. As a result, Hg(II) is released from the T−Hg(II)−T complexes. The guanine-rich sequences released from the H-DNA are then self-assembled with potassium ion to form a stable G-quadruplex conformation. In solutions of high ionic strength, this results in aggregation of AuNPs and a color change from red to blue which can be seen with bare eyes. The method is highly sensitive and selective. It has a linear response in the 10 pM to 100 nM Hg(II) concentration range, and the detection limit is as low as 3.2 pM (at an S/N ratio of 3). The relative standard deviation at a level of 0.5 nM of Hg(II) is 4.9% (for n = 10). The method was applied to the detection of Hg(II) in spiked environment water samples, with recoveries ranging from 92% to 106%.
A conformation-dependent colorimetric system was fabricated for label-free detection of mercury(II) by utilizing exonuclease III(Exo III)-assisted target recycling and gold nanoparticles (AuNPs).
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International Journal of Analytical Chemistry
·
2024
·
IF 1.5
Bingyuan Fan,Qian Wang,Shan Wang,Yahui Gao,Yan Liang,Jinru Pan,Xinrui Fu,Li Li,Wei Meng
MiR-378 is abnormally expressed in various cancers, such as hepatocellular carcinoma, renal cell carcinoma, and nonsmall cell lung cancer. Here, we developed a label- and immobilization-free ratiometric homogeneous electrochemical strategy based on exonuclease III (Exo III) for the facile and rapid determination of miR-378. Two 3′-protruding hairpin DNA probes (HPs) are designed in this strategy. Doxorubicin (DOX) and potassium ferrocyanide (Fe 2+ ) were used as label-free probes to produce a response signal (I DOX ) and a reference signal (I Fe 2+ ) in the solution phase. When no target was present in the solution, the HP was stable, most of the DOX was intercalated in the stem of the HP, and the diffusion rate of DOX was significantly reduced, resulting in reduced electrochemical signal response. When miR-378 was present, double-cycle signal amplification triggered by Exo III cleavage was initiated, ultimately disrupting the hairpin structures of HP1 and HP2 and releasing a large amount of DOX into the solution, yielding a stronger electrochemical signal, which was low to 50 pM. This detection possesses excellent selectivity, demonstrating high application potential in biological systems, and offers simple and low-cost electrochemical detection for miR-378.
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NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 15
·7613-7620
·
IF 3.269
Qianqian Pei,Yu Wang,Su Liu,Yifei Qin,Xueqi Leng,Xuejun Cui,Jiadong Huang
In this study, a novel electrochemical biosensor based on exonuclease III (Exo III)-aided autonomous cascade signal amplification for ultrasensitive and highly specific detection of Salmonella typhimurium (S. typhimurium) has been reported. Herein, two duplex DNA probes were ingeniously designed. An Ap–Pr duplex probe was constructed as a recognition element by hybridizing an S. typhimurium aptamer (Ap) with a primer (Pr). A P–S duplex probe has been designed to contain a protruding DNA fragment at 5′-termini that has an identical sequence with Pr (the secondary Pr), a complementary duplex DNA that is used for blocking a signal-triggered probe (S), and an overhung nucleic acid segment at 3′-end that can anneal with Pr and form double-stranded DNA with a blunt 3′-terminus, thus initiating Exo III-aided amplification reaction. Upon sensing of the target S. typhimurium, the specific recognition of S. typhimurium and aptamer releases Pr, which anneals with the P–S duplex and triggers the Exo III cleavage reaction, accompanied by release of Pr, S, and secondary Pr. After this, the released Pr and secondary Pr anneal with other P–S duplex, which in turn triggers the Exo III-assisted cycling cleavage. Thus, large amounts of S are liberated, which hybrids with S* (DNA probe complementary to S); thereby, 5′-methylene blue (MB)-labelled DNA probe (MBP) folds into a hairpin structure with 5′-terminus close to electrode surface for efficient electronic transfer. Moreover, the S–S* hybrid duplex is specifically hydrolyzed by Exo III to liberate S, which accordingly results in the cycling cleavage of S*. Therefore, numerous MBP transform into a hairpin structure with electroactive MB close to the electrode surface; this generates significantly amplified electrochemical signal towards S. typhimurium detection. The present developed strategy exhibited high sensitivity towards S. typhimurium with a detection limit of 2.8 × 10 cfu mL−1. Furthermore, the proposed autonomous cascade signal amplification strategy can be easily extended for detection towards a wide spectrum of analytes including nucleic acid, proteins, and small molecules possessing their corresponding aptamers. Therefore, the developed Exo III-aided autonomous cascade signal amplification strategy might indeed provide a facile and universal tool for bioanalysis and clinical diagnosis.
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MICROCHIMICA ACTA
·
2021
·Vol. 188
·期 8
·1-9
·
IF 5.833
Yang Jiao,Fu Shilan,Luo Fang,Guo Longhua,Qiu Bin,Lin Zhenyu
MicroRNAs can serve as biomarkers for many cancers, so it is significant to develop simple and sensitive strategies for microRNAs detection. Photoelectrochemical (PEC) detection has the advantages of simple equipment and high sensitivity. But in conventional PEC DNA sensors, tedious immobilization procedures of photoactive materials and capture probes on electrode surfaces are inevitable. To overcome those limitations, a homogeneous PEC biosensor based on target-responsive hydrogels has been developed (miRNA-155 has been chosen as a model target). PEC signal molecules (TiO 2 nanoparticles, TiO 2 NPs) were embedded in DNA hydrogels formed by hyaluronic acid sodium salt, amine-modified DNA double strands, and polyethylenimine rich in amine groups. In the presence of the target, DNA double strands in hydrogel were nicked by endonuclease and TiO 2 NPs were released to the supernate and a high PEC response was obtained when collecting the supernate for PEC test, while almost no TiO 2 NPs released in the absence of the target. Thanks to the exonuclease III and nicking endonuclease Nb.BbvCI-assisted cascaded amplification strategy, the proposed biosensor exhibits high sensitivity toward miRNA-155 with a low detection limit of 0.41 fM and a wide linear range from 1.0 fM to 100 pM. Since this method circumvents tedious electrode modification procedures, the proposed technique exhibits the advantages of simplicity and good reproducibility. Moreover, the prepared hydrogels have outstanding storage stability, so that they can be prepared in advance and shorten detection time. This biosensing platform provides a versatile strategy for the construction of homogeneous PEC biosensors for the detection of diverse targets. Graphical abstract
Photoelectrochemical detection techniques have been coupled with controlled release system to develop an immobilization-free microRNA biosensor. High sensitivity has been realized based on cascaded signal amplification strategy, and the proposed biosensor has been applied to detect the target in real sample with satisfied results. Since no tedious electrode modifications, the proposed homogeneous PEC sensor exhibits high reproducibility and good stability.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Xiao Yang,Minghui Feng,Jianfei Xia,Feifei Zhang,Zonghua Wang
A novel electrochemical biosensor based on AuNPs/Ti 3 C 2 MXene three-dimensional nanocomposite for sensitive miRNA-155 detection by exonuclease III (Exo III)-aided cascade target recycling is reported. Ti 3 C 2 MXene is synthesized and used as a support to immobilize Au nanoparticles (AuNPs) due to its special layered structure and metallic properties. The three-dimensional (3D) structure of the AuNPs/Ti 3 C 2 MXene nanocomposite for the biosensor platform leverages the integrated advantages of a large specific surface area, excellent electrical conductivity and electrocatalytic properties . AuNPs are used to immobilize capture DNA (C-DNA) by Au S chemical bonds. The C-DNA was modified with methylene blue (MB) at the 3′ end, resulting in an initial DPV electrochemical signal ( I d ). In the presence of target, miRNA-155 and C-DNA formed a double-stranded structure by complementary base pairing. Subsequently, Exo III digested the 3′ end of the C-DNA in the double-stranded structure and caused the electrochemical signal to “turn off” (the final signal denoted as I h ). By Exo III-aided cascade cleavage of the target, one miRNA-155 chain causes the release of several C-DNAs under certain conditions, which significantly amplifies the peak current difference on the fabricated biosensor (Δ I = I d ﹣ I h ). The electrochemical sensor achieved a detection limit of 0.35 fM (S/N = 3) with a linear range from 1.0 fM to 10 nM. This sensor also shows desirable stability, reproducibility and specificity.
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