JOURNAL OF HAZARDOUS MATERIALS
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2023
·
IF 13.6
Liubing Kong,Ying Gan,Tianxing Wang,Xianyou Sun,Chiyu Ma,Xinyi Wang,Hao Wan,Ping Wang
Okadaic acid (OA), one of the most widely distributed marine toxins worldwide poses a severe threat to human health. Previous sensing methods for OA detection are usually based on antigen-antibody binding mechanism. However, the drawbacks of antibodies especially the enzyme-labeled antibodies, such as the harsh storage condition and high cost, lead to significant challenges to OA detection in biological samples. To overcome these limitations, a single-stranded DNA binding protein (SSB) coupled aptasensor was developed for OA detection. SSB was incubated on the microplate as a substitute for conventional OA-protein conjugations. Carbon-gold nanoparticles were synthesized and labeled with horseradish peroxidase and thiol-modified aptamers to obtain a capture probe ( [email protected] ) instead of the enzyme-labeled antibody for signal amplification. OA and SSB competed to bind with limited aptamers on [email protected] probes followed by colorimetric assay to obtain the optical signals correlated to OA concentration. To achieve on-site detection, a miniaturized and multichannel absorbance reader (Smart-plate reader) was self-designed with full automation for OA detection. Utilizing the SSB coupled aptasensor and the Smart-plate reader, our approach enables cost-effective and on-site OA sensing with a detection range of 2.5–80 ppb and an ultra-low limit of detection of 0.68 ppb. Moreover, novel OA detection kits based on the SSB coupled aptasensor were prepared which can effectively reduce the cost by 15 times lower than that of commercial ELISA kits. Therefore, the developed platform provides a favorable and promising avenue for marine toxin detection in aquaculture and food safety.
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ANALYST
·
2018
·Vol. 143
·期 20
·4915-4922
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IF 3.864
Ya-Fei Tian,Cui-Fang Ning,Fang He,Bin-Cheng Yin,Bang-Ce Ye
Exosomes, as important signal transmitters, play a key role in intercellular communication, especially in cancer metastasis. There is considerable evidence that exosomes can be used as an indicator of cancer. However, convenient and sensitive methods for detecting exosomes are still technically challenging. Here, we present a convenient and highly sensitive surface-enhanced Raman scattering (SERS) based method by combining immunoaffinity, SERS nanoprobes, and portable Raman devices for specific isolation and accurate quantification of exosomes. To construct the SERS-based biosensor, the surfaces of gold nanostar@4-mercaptobenzoic acid@nanoshell structures (AuNS@4-MBA@Au) are modified with a bivalent cholesterol (B-Chol)-labeled DNA anchor to prepare SERS nanoprobes. Exosomes are specifically captured by immunomagnetic beads, and then SERS nanoprobes are fixed on the surface of exosomes by hydrophobic interactions between cholesterol and lipid membranes, thus forming a sandwich-type immunocomplex. The immunocomplex can be magnetically captured and produce enhanced SERS signals. In the absence of exosomes, the sandwich-type immunocomplex cannot be formed, and thus negligible SERS signals are detected. The degree of immunocomplex assembly and the corresponding SERS signals are positively correlated with the exosome concentration over a wide linear range of 40 to 4 × 107 particles per μL and the limit of detection is as low as 27 particles per μL. Consequently, a sensitive and simple strategy for detection of exosomes is successfully constructed. We believe that our biosensor has considerable potential as a convenient and highly sensitive quantification tool to detect exosomes in biological samples.
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International Journal of Nanomedicine
·
2018
·
IF 4.37
Fei Yu,Ya-min Xiong,Song-cheng Yu,Lei-liang He,Shan-shan Niu,Yu-ming Wu,Jie Liu,Ling-bo Qu,Li-e Liu,Yong-jun Wu
Background DNA methyltransferase 1 (DNMT1), a dominant enzyme responsible for the transfer of a methyl group from the universal methyl donor to the 5-position of cytosine residues in DNA, is essential for mammalian development and closely related to cancer and a variety of age-related chronic diseases. DNMT1 has become a useful biomarker in early disease diagnosis and a potential therapeutic target in cancer therapy and drug development. However, till now, most of the studies on DNA methyltransferase (MTase) detection have focused on the prokaryote MTase and its activity. Methods A magnetic fluorescence-linked immunosorbent assay (FLISA) using CdSe/ZnS quantum dots as fluorescent probes was proposed for the rapid and sensitive detection of the DNMT1 level in this study. Key factors that affect the precision and accuracy of the determination of DNMT1 were optimized. Results Under the optimal conditions, the limit of detection was 0.1 ng/mL, the linear range was 0.1–1,500 ng/mL, the recovery was 91.67%–106.50%, and the relative standard deviations of intra- and inter-assays were respectively 5.45%–11.29% and 7.03%–11.25%. The cross-reactivity rates with DNA methyltransferases 3a and 3b were only 4.0% and 9.4%, respectively. Furthermore, FLISA was successfully used to detect the levels of DNMT1 in human serum samples, and compared with commercial enzyme-linked immunosorbent assay (ELISA) kits. The results revealed that there was a good correlation between FLISA and commercial ELISA kits (correlation coefficient r =0.866, p =0.001). The linear scope of FLISA was broader than ELISA, and the measurement time was much shorter than ELISA kits. Conclusion These indicated that the proposed FLISA method was sensitive and high throughput and can quickly screen the level of DNMT1 in serum samples.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Hong Zhang,Zhigao Zhang,Longyang Han,Mingqin Zhao,Pengfei Liu,Zhen Luo
Aflatoxin B 1 (AFB 1 ) has seriously threatened human health, so it is vital to construct an efficient detection strategy for AFB 1 analysis. An exquisitely designed ratiometric electrochemical aptasensor for sensitive detection of AFB 1 has been successfully developed in this work. DNA tetrahedral scaffold (DTS) is used to fix the DNA probes, 3D DNAzyme walker is employed to amplify the detection signals, and the composite material AuNP/ZIF-67/g-C 3 N 4 acts as the sensing surface of the detection electrode. In the presence of AFB 1 , the 3D DNAzyme walker induced the release of the oligonucleotide attached ferrocene (Fc) from the detection electrode and is simultaneously grafted the DNA-modified methylene blue (MB) onto the electrode, leading to a seesaw-like ratiometric electrochemical aptasensor. This ratiometric electrochemical aptasensor provides an outstanding AFB 1 analysis in the linear range of 2.0 fg·mL −1 to 1.0 ng·mL −1 with the limit of detection (LOD) 0.67 fg·mL −1 . It provides new idea for the analysis of other contaminants in foodstuffs.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Jingqi Sun,Jiaxin Li,Yanzhi Xing,Han Leng,Wei Chen,Yanfeng Zhang,Xuwei Chen
Adenine DNA glycosylase (MutY) is a crucial member of DNA glycosylase family, and the abnormal expression of the human MutY homologs is associated with the pathogenesis of various diseases, therefore, convenient and cost-effective assessing the activity of MutY holds significant biological and medical importance. Herein, the precise identification/excision capacity of MutY to mismatched G-A base pair of dsDNA chains and the DNA-template-dependant fluorescence behaviors of copper nano cluster (CuNCs) was exploited for the accurate sensing of active MutY. Hairpin DNA with G-A base mismatch was excised by MutY to produce dsDNA chains with repetitive AAT-TTA base pairs. The newly formed dsDNA provided more active sites for the growth of CuNCs compared to the original hairpin DNA, resulting in the significantly enhanced fluorescence of final CuNCs. MutY was accurately quantified with a detection limit of 9.98 nmol L −1 . The developed sensing protocol exhibited excellent selectivity toward MutY over various ions, neutral biomolecules, and protein species. Most importantly, The sensing system is capable to distinguish the active MutY from other MutY homologs with low activity, e.g., de-[4Fe4S] cluster MutY (DIS-MutY), and the practicality was well demonstrated by detecting active MutY contents in various cell lysates.
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ANALYST
·
2017
·Vol. 142
·期 14
·2617-2623
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IF 3.885
Yan Xiao,Yuhao Sheng,Jie Zhou,Miaomiao Chen,Wei Wen,Xiuhua Zhang,Shengfu Wang
Graphitic carbon nitride (g-C3N4) nanosheets are a type of two-dimensional nanomaterial with stable photoluminescence and large specific surface areas that make them an ideal candidate for fluorescence sensing. However, fluorescence sensing based on g-C3N4 nanosheets for disease-specific biomolecules is still limited. Moreover, current g-C3N4 nanosheet-based fluorescence sensors for nucleic acid require pre-labeling which is time-consuming and cost-ineffective. In this work, a novel label-free strategy for HBV gene determination based on metal ion binding-induced fluorescence quenching of g-C3N4 nanosheets was designed. Under the optimized conditions, this bioassay provided high sensitivity for HBV gene determination with the limit of detection as low as 1.0 nM, and has been successfully applied for the detection of HBV gene in human serum with satisfactory results. By embedding different recognition sequences of the probes, this method may be conveniently used for versatile detection of diverse disease markers. This novel design may provide a simple, flexible, sensitive and low-cost strategy for g-C3N4 nanosheet-based disease-specific biomolecule sensing.
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ANALYTICAL CHEMISTRY
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2017
·
IF 6.32
Bingzhi Li,Lei Xu,Yue Chen,Wanying Zhu,Xin Shen,Chunhong Zhu,Jieping Luo,Xiaoxu Li,Junli Hong,Xuemin Zhou
Transcription factors (TFs) regulate gene expression by binding to regulatory regions, and their dysregulation is involved in numerous diseases. Thus, they are therapeutic targets and potential diagnostic markers. However, widely used methods for TFs detection are either cumbersome or costly. Herein, we first applied DNA-Ag nanoclusters molecular beacons (AgMBs) in TFs analysis and designed an assay based on the switchable fluorescence of AgMBs. In the absence of TFs, a single-stranded DNA functioned as a reporter is released from a double-stranded DNA probe (referred as dsTFs probe) under exonuclease III (Exo III) digestion. Then, the reporter triggers downstream Exo III-assisted signal amplification by continuously consuming the guanine-rich enhancer sequences in AgMBs, resulting in significant fluorescent decrease eventually. Conversely, the presence of TFs protects the dsTFs probe from digestion and blocks the downstream reaction to keep a highly fluorescent state. To testify this rationale, we utilized nuclear factor-kappa B p50 (NF-κB p50) as a model TFs. Owing to the amplification strategy, this method exhibited high sensitivity toward NF-κB p50 with a limit of detection of 10 pM, and a broad linear range from 30 pM to 1.5 nM. Furthermore, this method could detect multiple TFs in human colon cancer DLD-1 cells and reflect the variation in their cellular levels after stimulation. Finally, by conducting an inhibition assay we revealed the potential of this method for screening TFs-targeted drugs and calculating the IC50 of corresponding inhibitors.
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ELECTROANALYSIS
·
2015
·Vol. 27
·期 9
·2201-2208
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IF 2.138
Qianjie Xie,Xiang-yu Chen,Hanzhi Zhang,Mengdi Liu,Qian Wang,Xin Zhang,Yehua Shen,Fengchun Yang
A Fe 3 O 4 -graphene oxide hybrid composite (Fe 3 O 4 GO) was synthesized and used to construct a novel electrochemical sensor for the simultaneous detection of adenine and guanine. The Fe 3 O 4 GO based electrochemical sensor exhibits linear ranges of 0.05–25 μM and 0.05–25 μM with detection limits of 4 nM and 3 nM for adenine and guanine, respectively. This method was applied in the determination of guanine and adenine in many samples with satisfying results. The value of (G+C)/(A+T) in DNA was calculated to be 0.7536. The sensor exhibits some advantages, such as rapidity, good reproducibility and long-term stability.
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BIOSENSORS & BIOELECTRONICS
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2013
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IF 5.437
Huanshun Yin,Yunlei Zhou,Zhenning Xu,Mo Wang,Shiyun Ai
In this work, we fabricated a novel electrochemical immunosensor for detection of DNA methylation , analysis of DNA MTase activity and screening of MTase inhibitor. The immunosensor was on the basis of methyl binding domain protein of MeCP2 as DNA CpG methylation recognization unit, anti-His tag antibody as “immuno-bridge” and horseradish peroxidase labeled immuneglobulin G functionalized gold nanoparticles (AuNPs–IgG–HRP) as signal amplification unit. In the presence of M. Sss I MTase, the symmetrical sequence of 5′-CCGG-3′ was methylated and then recognized by MeCP2 protein. By the immunoreactions, anti-His tag antibody and AuNPs–IgG–HRP was captured on the electrode surface successively. Under the catalysis effect of HRP towards hydroquinone oxidized by H 2 O 2 , the electrochemical reduction signal of benzoquinone was used to analyze M. Sss I MTase activity. The electrochemical reduction signal demonstrated a wide linear relationship with M. Sss I concentration ranging from 0.05 unit/mL to 90 unit/mL, achieving a detection limit of 0.017 unit/mL (S/N=3). The most important advantages of this method were its high sensitivity and good selectivity , which enabled the detection of even one-base mismatched sequence. In addition, we also verified that the developed method could be applied for screening the inhibitors of DNA MTase and for developing new anticancer drugs.
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Advanced Healthcare Materials
·
2013
·Vol. 3
·期 4
·596-608
·
IF 0
Bin Yang,Huizhen Jia,Xuli Wang,Si Chen,Xianzheng Zhang,Renxi Zhuo,Jun Feng
By exploiting boronic acid coupling and host–guest chemistry, a pH-responsive drug/gene co-delivery nanoplatform is designed for cancer treatments with the excellently serum-tolerant transfection activity and the capability to load and release hydrophobic drugs in an acidity-accelerated manner. Via boronate linkage, γ -CD is allowed to spontaneously attach onto phenylboronic-acid-modified oligoethylenimine (PEI1.8K-PB 2.9 ) at neutral condition. The formed vehicle/DNA nanoformulation is thus surrounded densely by γ -CD moieties to biomimic the carbohydrate-rich cell surface, providing a novel approach to overcome serum-susceptible drawbacks frequently associated with synthetic gene carriers. PEI1.8K-PB 2.9 - γ -CD conjugates demonstrate significantly improved cell-biocompatibility and transfection activity over PEI1.8K-PB 2.9 . Noticeably, serum-associated inhibition effect is negligible for PEI1.8K-PB 2.9 - γ -CD-mediated transfection whereas marked transfection reduction occurs for PEI25K and PEI1.8K-PB 2.9 upon serum exposure. Consequently, PEI1.8K-PB 2.9 - γ -CDs afford much higher transfection efficiency, that is, 25-fold higher luciferase expression over PEI25K in presence of 30% serum. An anticancer drug of doxorubicin (DOX) is shown to be readily accommodated into the nanoformulation via host–guest chemistry and intracellularly co-delivered together with plasmid DNA. Due to the acidity-labile feature of boronate linkage, DOX/ γ -CD inclusion complexes would be mostly detached from the nanoformulation triggered by acidity, leading to faster drug release. Furthermore, drug inclusion does not alter the serum-compatible transfection efficiency of PEI1.8K-PB 2.9 - γ -CD.
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ANALYTICA CHIMICA ACTA
·
2015
·
IF 4.513
Chaohui Chen,Ningxing Li,Jingwen Lan,Xinghu Ji,Zhike He
A target-catalyzed hairpin assembly (CHA) and graphene/Au-NPs hybrids-based platform has been developed for the determination of DNA . This new sensor not only avoided any labeling but also reduced the background signal. In the absence of target, the assembly of H1 and H2 couldn't be triggered. The catalytic activity of graphene/Au-NPs hybrids was inhibited by adsorption of H1 and H2, leading to the “inactive” hybrids unable to catalyze the oxidation reaction of 3,3′,5,5′-tetramethylbenzidine (TMB). However, with the addition of target DNA, the target-catalyzed hairpin assembly was initiated and produced plenty of H1–H2 duplex, which had a weak binding affinity with the graphene/Au-NPs. Thus, the protected interface of graphene/Au-NPs hybrids became active and catalyzed the oxidation reaction of TMB accompanied with a colorless to-blue color change. This approach exhibited good sensitivity and specificity for target DNA with a detection limit of 5.74 × 10 −11 M, and realized the assay of target DNA in human serum samples. Besides, this sensor could be further expanded to detect viruses or proteins by adapting the corresponding aptamers, showing great potential in biochemical detections.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2017
·
IF 3.887
Aijie Guo,Yun Wang,Shaohui Xu,Xiao Zhang,Min Li,Qing Liu,Yuanyuan Shen,Derong Cui,Shengrong Guo
Because the surface of the cationic polymer gene complex is positively charged, it can result in problems such as poor blood stability and cytotoxicity. Therefore, reducing the positive charge of the cationic gene complex without affecting its transfection efficiency is crucial. To achieve this objective, a pH -responsive charge-convertible ternary complex was developed in this study. Modified plyethylenimine (PEI) with two different degrees of substitution of NH 2 (plyethylenimine-1,2-cyclohexanedicarboxylic anhydride, PEI-CCA, and folic acid-plyethylenimine-1,2-cyclohexanedicarboxylic anhydride, FA-PEI-CCA) were first obtained by a chemical graft reaction. PEI-CCA and FA-PEI-CCA have significantly lower cytotoxicities and much better blood compatibilities than PEI does, and the former have an undifferentiated compression capability of DNA . The zeta potential values of the as-prepared ternary complexes (PEI-CCA/PEI/DNA and FA-PEI-CCA/PEI/DNA) were negative at pH 7.4 and positive at pH 6.5, with particle sizes of approximately 150 nm. MTT assays demonstrated the significantly lower cytotoxicities of the ternary complexes compared to that of PEI/DNA. Moreover, the cytotoxicities of the ternary complexes were lower at pH 7.4 than pH 6.5. Transfection experiments in vitro revealed that the mean fluorescence intensities and transfection efficiencies of the ternary complexes were lower than for PEI/DNA at pH 7.4 but were almost the same at pH 6.5. The ternary complex with a FA group had significantly higher mean fluorescence intensity and transfection efficiency than did the ternary complex without it. In addition, the transfection experiment in 293T cells preliminarily validated the targeting function of the FA group of the ternary complex.
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