ACS Applied Bio Materials
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2020
·
IF 0
Yu Wang,Xudong Zhao,Bingyang Huo,Shuyue Ren,Jialei Bai,Yuan Peng,Shuang Li,Dianpeng Han,Jiang Wang,Tie Han,Zhixian Gao
Application of nanotechnology to detection can effectively increase the biocompatibility of detection sensors. However, since the traditional signal output element has a high background value, the detection sensitivity is often limited. Here, we designed a fluorescence aptasensor based on hybridization chain reaction (HCR) and triplex structure (TS). The aptamer was competitively bound by bisphenol A (BPA) and complementary DNA (cDNA). Unbound cDNA was obtained by magnetic separation. HCR could be triggered by cDNA to form long double-stranded DNA (dsDNA) products. The upconversion nanoparticle (UCNP)-modified ssDNA can form a TS with the HCR product. Thereby, the distance between the UCNPs and Dabcyl on the hairpin was brought closer, and fluorescence was quenched to generate a signal change. HCR and the low background value of UCNPs could improve the sensitivity of detection. The aptasensor has a detection limit as low as 0.057 ng/mL and has been successfully applied to actual sample detection. Its high sensitivity, strong specificity, and excellent biocompatibility make it promising for other target detection and clinical diagnosis.
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Nanoscale
·
2020
·Vol. 12
·期 44
·22574-22585
·
IF 6.895
Tian Gao,Pi Ding,Wenjing Li,Zhili Wang,Qiao Lin,Renjun Pei
Circulating tumor cells (CTCs) acquire mesenchymal markers (e.g., N-cadherin) and lose epithelial markers (e.g., epithelial cell adhesion molecule, EpCAM) during the epithelial-mesenchymal transition (EMT) and are therefore ideal biomarkers of tumor metastasis. However, it is still a challenge to efficiently capture and detect circulating tumor cells with different phenotypes simultaneously. In this work, to obtain aptamers targeting N-cadherin in the native conformation on live cells, we established stable N-cadherin overexpressing cells (N-cadherin cells) and used these cells to identify a panel of N-cadherin-specific aptamers through the cell-SELEX approach. Two aptamer candidates obtained after 12 rounds of selection showed a low equilibrium dissociation constant in the nanomolar range, indicating high binding affinity. The truncated aptamer candidate NC3S showed the highest binding affinity to N-cadherin cells with a low Kd value of 20.08 nM. The SYL3C aptamer was reported to target cancer cell surface biomarker EpCAM. Then, we synthesized two kinds of aptamer-modified magnetic nanoparticles (SYL3C-MNPs and NC3S-MNPs). Both SYL3C and NC3S aptamers possess excellent capture specificity and efficiency for the target cells. The aptamer–MNP cocktail exhibits a considerable capture efficiency and sensitivity for rare cancer cells of epithelial and mesenchymal phenotypes. Furthermore, no CTCs were found in blood samples from healthy donors, while CTCs were successfully isolated by using the aptamer–MNP cocktail for 15 out of 16 samples collected from patients. In summary, the two kinds of aptamer-modified MNPs could be utilized as a promising tool for capturing CTCs from clinical samples.
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PubMed
高影响因子
Frontiers in Chemistry
·
2020
·
IF 3.693
Wang Yue,Lv Menghua,Chen Zehan,Deng Zilong,Liu Ningtao,Fan Jianwei,Zhang Weixian
We report a new sensor for the specific detection of lead ions (Pb2+) in contaminated water based on fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) as donors and gold nanoparticles (Au NPs) as receptors. The UCNPs modified with Pb2+ aptamers could bind to Au NPs, which were functionalized with complementary DNA through hybridization. The green fluorescence of UCNPs was quenched to a maximum rate of 80% due to the close proximity between the energy donor and the acceptor. In the presence of Pb2+, the FRET process was broken because Pb2+ induced the formation of G-quadruplexes from aptamers, resulting in unwound DNA duplexes and separated acceptors from donors. The fluorescence of UCNPs was restored, and the relative intensity had a significant linear correlation with Pb2+ concentration from 0 to 50 nM. The sensor had a detection limit as low as 4.1 nM in a buffer solution. More importantly, the sensor exhibited specific detection of Pb2+ in complex metal ions, demonstrating high selectivity in practical application. The developed FRET prober may open up a new insight into the specific detection of environmental pollution.
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PubMed
高影响因子
MICROCHIMICA ACTA
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2020
·Vol. 187
·期 5
·1-9
·
IF 6.232
Cao Chen,Liu Jinquan,Tang Shuangyang,Dai Zhongran,Xiao Fubing,Rang Weiqing,Liu Ling,Chen Tuo,Yuan Yali,Li Le
A superior electrochemical biosensor was designed for the determination of UO 2 2+ in aqueous solution by integration of DNAzyme and DNA-modified gold nanoparticle (DNA-AuNP) network structure. Key features of this method include UO 2 2+ inducing the cleavage of the DNAzyme and signal amplification of DNA-AuNP network structure. In this electrochemical method, the DNA-AuNP network structure can be effectively modified on the surface of gold electrode and then employed as an ideal signal amplification unit to generate amplified electrochemical response by inserting a large amount of electrochemically active indicator methylene blue (MB). In the presence of UO 2 2+ , the specific sites on DNA-AuNP network structure can be cleaved by UO 2 2+ , releasing the DNA-AuNP network structure with detectable reduction of electrochemical response intensity. The electrochemical response intensity is related to the concentration of UO 2 2+ . The logarithm of electrochemical response intensity and UO 2 2+ concentration showed a wide linear range of 10~100 pM, and the detection limit reached 8.1 pM (S/ N = 3). This method is successfully used for determination of UO 2 2+ in water samples.
Fabricated DNAzyme network structure for enhanced electrical signal. Numerical experiments show that the current signal decreases as the concentration of UO 2 2+ increases. It can be seen that the biosensors could be used to detect UO 2 2+ in aqueous solution effectively.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Jianhui Liu,Deyu Kong,Zhen Liu,Hanbiao Liu,Jiangle Yi,Dong Tian,Fangquan Xia,Changli Zhou
In this paper, a novel amino-functionalized mesoporous dendritic fibrous nanosilica (NH 2 -DFNS) was used as DNA amplification platforms with DNA generated electrochemical signal as target conversion strategy to establish an electrochemical aptasensor for chlorpyrifos residues. The signal generation was based on the electrochemical reaction between molybdate with phosphate groups on the aptamer molecules, which greatly simplified the signal transduction and preparation steps of aptasensor, so as to improve the sensitivity of the aptasensor. The NH 2 -DFNS was prepared by a simple microemulsion method and characterized by SEM, TEM, FT-IR, BET, as well as XPS techniques. Importantly, the results showed that such a sphere-shaped nanomaterial with three-dimensional (3D) centerradial channels and hierarchical pores supported abundant DNA to amplify the DNA generated signal in the aptasensor. Furthermore, this aptasensor for detection of chlorpyrifos showed good sensitivity with a linear range of 1.0 fM∼1.0 nM, a detection limit of 0.43 fM. In addition, this sensor also possessed excellent specificity, repeatability, and stability. Moreover, this proposed electrochemical aptasensor was successfully used for the detection of chlorpyrifos residues in several practical samples.
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高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Zixin Zhou,Zijing Gao,Hao Shen,Mengqi Li,Wenting He,Ping Su,Jiayi Song,Yi Yang
In recent years, metal–organic frameworks (MOFs) have been extensively studied as candidate enzyme immobilization platforms. However, conventional MOF–enzyme composites usually exhibit low controllability and reusability. In this study, a novel and stable strategy for enzyme immobilization was designed by use of ZIF-8 to encapsulate in situ DNA–enzyme composites on the surface of magnetic particles (MPs). The mechanism of in situ encapsulation was discussed in detail. It was found that immobilized enzymes were involved in the growth of ZIF-8, and the DNA cross-linking agents promoted the growth of ZIF-8 on the surface of MP. The thermal, chemical, and physical stabilities of horseradish peroxidase (HRP) were all significantly enhanced after in situ encapsulation. Most importantly, this strategy was proven to be a general platform that can be used to stabilize various proteins. The in situ encapsulation strategy was expanded to immobilize a cascade of enzymes, and ZIF-8@MPGOx–HRP possessed high selectivity and a wide linear range (25–500 μM) for glucose detection.
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高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Yixia Yang,Behafarid Ghalandari,Liyun Lin,Xiao Sang,Wenqiong Su,Adeleh Divsalar,Xianting Ding
The abuse application of glyphosate can result in a potential hazard for environment and human, however its ultrasensitive detection remains challenging. Herein, a Cu 2+ modulated DNA-templated silver nanoclusters (DNA-AgNCs) sensor was constructed to sensitively determine glyphosate based on the turn-on fluorescence strategy. The fluorescence quenching of DNA-AgNCs occurred with the existence of Cu 2+ . Upon the presence of glyphosate, the functional groups on the surface of glyphosate could chelate with Cu 2+ , following the fluorescence recovery of DNA-AgNCs. Through the stoichiometric methods, we unveil that Cu 2+ -trigged fluorescence quenching mode is a combination of static and dynamic quenching with the static mode being predominant. In DNA-AgNCs/Cu 2+ system, the carboxylate, amine, and phosphonate groups of glyphosate interact with Cu 2+ through chelation, in which the carboxylate oxygen, the phosphonate oxygen atoms, and the monoprotonated secondary amine nitrogen atom and Cu 2+ form chelate rings. This fluorescence sensor showed a desired linearity of glyphosate analysis under the optimum conditions, ranging from 15 to 100 μg/L with a low detection down to 5 μg/L. Moreover, the proposed sensor was successfully utilized to measure glyphosate in real samples, indicating a promising application in pesticide residues detection.
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高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Wenting He,Hao Shen,Zixin Zhou,Ze Huang,Hao Chao,Jiayi Song,Ping Su,Yi Yang
Metal-organic frameworks (MOFs) are excellent platforms for enzyme immobilization. However, strong or weak interactions between enzymes and MOFs often lead to inactivation and enzyme leaching. Herein, single-stranded DNA (ssDNA) with Janus properties was used as a linker between enzymes and the dual carriers of MOFs and graphene oxide (GO), which provided a simple and effective platform to tightly co-immobilize glucose oxidase (GO X ) and horseradish peroxidase (HRP). Mechanistic investigation revealed that the enzyme was immobilized mainly through π-π stacking between nucleobases and GO and coordination of the sugar-phosphate backbone with zirconium clusters in MOFs. This strategy ameliorated traditional surface adsorption issues for enzyme immobilization on MOFs. By introducing GO and ssDNA, the GO X &HRP cascade reaction on MOFs was enhanced significantly, showing better kinetics than the corresponding free GO X &HRP. Furthermore, the immobilized GO X &HRP exhibited substrate selectivity and a wide linear range for glucose detection. This enzyme immobilization strategy should have broad application prospects and practical value in biocatalysis and diagnostics.
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高影响因子
Frontiers in Immunology
·
2021
·
IF 7.561
Yu Zhengqing,Cao Wandi,Gao Xuchen,Aleem Muhammad Tahir,Liu Junlong,Luo Jianxun,Yan Ruofeng,Xu Lixin,Song Xiaokai,Li Xiangrui
Toxoplasma gondii (T. gondii) is an intracellular parasitic protozoan that can cause serious public health problems. However, there is no effectively preventive or therapeutic strategy available for human and animals. In the present study, we developed a DNA vaccine encoding T. gondii oxidoreductase from short-chain dehydrogenase/reductase family (TgSDRO-pVAX1) and then entrapped in chitosan and poly lactic-co-glycolic acid (PLGA) to improve the efficacy. When encapsulated in chitosan (TgSDRO-pVAX1/CS nanospheres) and PLGA (TgSDRO-pVAX1/PLGA nanospheres), adequate plasmids were loaded and released stably. Before animal immunizations, the DNA vaccine was transfected into HEK 293-T cells and examined by western blotting and laser confocal microscopy. Th1/Th2 cellular and humoral immunity was induced in immunized mice, accompanied by modulated secretion of antibodies and cytokines, promoted the maturation and MHC expression of dendritic cells, and enhanced the percentages of CD4+ and CD8+ T lymphocytes. Immunization with TgSDRO-pVAX1/CS and TgSDRO-pVAX1/PLGA nanospheres conferred significant immunity with lower parasite burden in the mice model of acute toxoplasmosis. Furthermore, our results also lent credit to the idea that TgSDRO-pVAX1/CS and TgSDRO-pVAX1/PLGA nanospheres are substitutes for each other. In general, the current study proposed that TgSDRO-pVAX1 with chitosan or PLGA as the delivery vehicle is a promising vaccine candidate against acute toxoplasmosis.
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高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Tingting Zhao,Min Zhang,Qi Peng,Xucong Lin,Zenghong Xie
Herein, a facile protocol of simple DNA adsorption on UV-initiated polymerization supports was proposed for effectively fabricating aptamer-based affinity monolithic column. Hydrophilic cationic monolith with an excellent mechanical stability was achieved within 7 min and then massive aptamers were directly bound by DNA charge-dependent adsorption. Strong cationic quaternary ammonium-based monomer was employed to provide effective and stable positive charge surface for aptamer immobilization in a wide range of pH. An ultra-high aptamer coverage density of 6813 pmol/μL was achieved to gain a highly specific online recognition performance. Limitations such as low aptamer capacity, tedious modification and time-consuming reactions in the traditional biological or covalent modification strategies were avoided. By using ochratoxin A (OTA) as the given analyte, the selective recognition and high recoveries were successfully achieved, and little cross-reactivity towards OTB analogue was only 0.5% even if the content of OTB got up to 125 folds of OTA. Applied to sample analysis, the satisfactory discriminations of trace OTA were obtained at 93.9 ± 1.9% – 96.5 ± 1.7%（n = 3）in beer, wheat and chicken liver samples. It might light a cost-effective access to efficiently preparing high-performance affinity monoliths towards the selective in-tube microextraction of OTA.
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高影响因子
FOOD CONTROL
·
2019
·
IF 4.248
Yuanyuan Hui,Bini Wang,Rong Ren,Aiqing Zhao,Fuxin Zhang,Shuanghong Song,Yaping He
It is very essential and meaningful for detection and quantitation of aflatoxin in food and agricultural commodities to establish a rapid and accurate detection method. Herein, a novel electrochemical aptasensor for sensitive and selective detection of aflatoxin B 1 (AFB 1 ) was successfully constructed. The thiolated complementary strand (cDNA) of the AFB 1 aptamer (Apt) was immobilized on the surface of the glassy carbon electrode (GCE) modified with gold nanoparticles (AuNPs) through Au–S bond. Then Apt was attached on the surface of GCE via by specific base pairing. In the presence of AFB 1 , the Apt was detached from the electrode surface by specific recognition between the AFB 1 and Apt, forming Apt-AFB 1 conjugates in solution. The conjugates were digested by exonuclease I ( Exo I) to trigger AFB 1 recycling. Finally, DNA-AuNPs-horseradish peroxidase (DNA-AuNPs-HRP) nanoprobes was bound with cDNA on the surface of electrode by specific base pairing. HRP could catalyze the oxidation of hydroquinone (HQ) to benzoquinone (BQ) by hydrogen peroxide (H 2 O 2 ) for producing a strong electrochemical signal. Under the optimized conditions, the electrochemical signals increased with increasing concentrations of AFB 1 in a range from 10 −3 ng mL −1 to 200 ng mL −1 with a low detection limit of 3.3 × 10 −4 ng mL −1 . Moreover, the aptasensor has been successfully applied for the determination of AFB 1 in peanuts and corn samples and the recoveries were 88.5 %–110.2%, which would provide a novel method for the rapid detection of AFB 1 in food samples.
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高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2019
·
IF 2.12
Yu Yang,Jiang-Yu Bian,Yu-Han Li,Hui-Chao Guan,Yan-Ru Tang,Yan-Ling Chen,Shu-Mei Yue
Six complexes including [Cd (bpt)(odc) 2 ] (1), [Ni(bpt)(odc) 2 ] (2), [Zn (bpt)(odc) 2 ] (3), [Zn (bpt)(1,4-ndc) 2 (H 2 O)] (4), [Cd (bpt)(1,4-ndc) 2 ] (5), [Cd (bpt)(Pta) 2 (H 2 O) 2 ] (6), {bpt = 2-(2 pyridyl)benzothiazole, H 2 odc = 4,4′-oxybisbenzoic acid, 1,4-H 2 ndc = naphthalene-1,4-dicarboxylic acid, Pta = terephthalic acid}, have been determined by single-crystal X-ray diffraction analysis, which shows that complexes 1–3 belong to monoclinic system with space group P2 1 /n, complex 4 and complex 6 belong to triclinic system with space group P-1, complex 5 belongs to monoclinic system with space group P2 1 /c. TD-DFT calculations for the complexes 3 was performed to explain the structures and electronic spectral properties. UV spectroscopy , fluorescence spectroscopy and viscosity were used to characterize the interaction of the CT-DNA complexes. The results indicate that complexes 1–6 have strong interaction with CT-DNA binding. All complexes exhibit an electrostatic or groove mode of binding with DNA . Furthermore, they also present that all complexes have strong ability to interact with DNA. It can effectively destroy the DNA acting on cancer cells. Therefore, we hope to provide a theoretical and scientific basis for the development of anti-cancer drugs.
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高影响因子
危险品化学品经营许可证（带存储）