ANALYST
·
2017
·Vol. 143
·期 3
·709-714
·
IF 3.885
Yueyue Yao,Xiuzhong Wang,Wenna Duan,Feng Li
A label-free, versatile and low-background chemiluminescence (CL) sensing strategy based on gold nanocluster catalysis combined with the separation of magnetic beads (MBs) was developed. Kanamycin was selected as the target analyte to exhibit the analytical performance of this platform. Two single-stranded DNA (named DNA1 and DNA2) are ingeniously designed. DNA1, containing an aptamer sequence of the targets, was firstly immobilized on the MBs which were modified with many amino groups by amidation reaction. DNA2 consists of 30 repeat adenosine bases (A30) at the 5′ terminal which were used to prepare AuNCs by a UV-light-assisted method and a 12 nucleotide sequence at the 3′ terminal which can easily hybridize with DNA1 to form a partly complementary double-stranded structure. In the presence of targets, the aptamer modified on MBs would combine with targets and lead to release the prepared DNA-templated AuNCs. After the magnetic separation, enrichment AuNCs in the supernatant can catalyze the CL substrate to produce a strong CL signal. The well-designed CL sensing strategy exhibited a low detection limit of 0.035 nM for kanamycin, and it also showed good selectivity and stability. Most importantly, different targets can be analyzed only by changing the aptamer sequence that is immobilized on the MBs. Therefore, the strategy we proposed here has provided a versatile sensing platform for sensitively detecting various biomolecules at low levels.
研究领域:
分析化学
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生物传感
·
纳米技术
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DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Xiao-Yuan Wang,Jian Lv,Qin Hong,Ze-Rui Zhou,Da-Wei Li,Ruo-Can Qian
H2O2 is an essential signaling molecule in living cells that can cause direct damage to lipids, proteins, and DNA, resulting in cell membrane rupture. However, current studies mostly focus on probe-based sensing of intracellular H2O2, and these methods usually require sophisticated probe synthesis and instruments. In particular, local H2O2 treatment induces cell membrane rupture, but the level of cell membrane destruction is unknown because the mechanical properties of the cell membrane are difficult to accurately determine. Therefore, highly sensitive and label-free methods are required to measure and reflect mechanical changes in the cell membrane. Here, using an ultrasmall quartz nanopipette with a tip diameter less than 90 nm as a nanosensor, label-free and noninvasive electrochemical single-cell measurement is achieved for real-time monitoring of cell membrane rupture under H2O2 treatment. By spatially controlling the nanopipette tip to precisely approach a specific location on the membrane of a single living cell, stable cyclic membrane oscillations are observed under a constant direct current voltage. Specifically, upon nanopipette advancement, the mechanical status of the cell membrane can be sensibly displayed by continuous current versus time traces. The electrical signals are collected and processed, ultimately revealing the mechanical properties of the cell membrane and the degree of cell apoptosis. This nanopipette-based nanosensor paves the way for developing a facile, label-free, and noninvasive strategy to assay the mechanical properties of the cell membrane during external stimulation at the single-cell level.
研究领域:
生物医学工程
·
细胞生物学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Zece Zhu,Lifan Zeng,Wei Li,Di Tian,Weilin Xu
Organic persistent luminescence is usually emitted from synthesized materials containing π units (aromatic rings, double bonds, etc.). It is challenging but desirable to develop organic materials from renewable resources with tunable persistent luminescence to reduce environmental impact. Herein, we proposed an effective method to enhance the luminescence of cellulose, the most abundant natural renewable material free of π units. It was found that removing the crystal water in cellulose would increase the compactness of molecular packing and stabilize the hydroxyl clusters of polysaccharide chains, consequently leading to significant enhancement of phosphorescence with lifetime up to subseconds. This dehydration induced luminescence enhancement was found in not only purified cellulose but also cellulose-contained substances such as papers, cottons, and many other plant tissues. This indicated easier access to cellulose-based luminescence materials without chemical purification. In addition, label-free time-resolved luminescence imaging of plant tissues was achieved on a smartphone-based apparatus, since endogenous cellulose is distributed extensively in plants. Compared with synthetical luminophores, cellulose is a renewable and biodegradable source abundant in nature, not only readily available but also environmentally friendly. We believe this method may be used to develop other sustainable organic luminescence materials with a lack of π units for various optical applications.
研究领域:
材料科学
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光学
·
可再生资源研究
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Yanling Feng,Yufei Liu,Chen Su,Xinghu Ji,Zhike He
Silicon nanodots (SiNDs) are currently appealing to extensive studies due to their low toxicity and unique optical and electrical properties. In this work, we obtained label-free SiNDs via a facile hydrothermal method. The approach offers advantages in terms of cheap reactants, easy operation and a short time. The quantum yield (QY) of the SiNDs is up to 32.8%, and the as-prepared nanoparticles exhibit strong fluorescence (FL), higher photostability and obviously longer FL lifetime. More importantly, these label-free SiNDs can be used as a highly sensitive pH sensor, which FL respond rapidly to pH fluctuations and reveal a good linear relationship. Also, a superior pH-reversibility was demonstrated. Different salt ions show a little influence on the pH-responsive behavior. The pH of real water samples were tested on the basis of the proposed SiNDs sensor and the results are satisfactory. Further, traditional SiNDs with Si H or Si C surfaces make them less water-soluble or sensitive to the pH. Whereas, our SiNDs feature amino-terminated surface and these amino groups are conducive to the pH sensitivity. In a word, this new, cheap, low-toxic, and effective fluorescent pH sensor based on label-free SiNDs would be a promising candidate in biological field.
研究领域:
生物化学
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材料科学
·
分析化学
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DOI
高影响因子
ANALYTICAL LETTERS
·
2022
·
IF 2.267
Hongjing Sun,Zheng Liu,Zhihong Li,Xinyue Ma,Zixuan Duan,Chunyan Sun
A simple and label-free fluorescent sensor based upon a specific DNAzyme (8–17 DNAzyme) and thiazole orange (TO) for monitoring Pb2+ in water samples was described. The 8–17 DNAzyme was formed by an enzyme strand (17E) and a partially complementary substrate strand (17DS). Thiazole orange, the DNA intercalator, was nonfluorescent in aqueous solution while it intercalates into the 8–17 DNAzyme with a duplex structure resulting in strong fluorescence. In the presence of Pb2+, the 17E was activated and cleaved the 17DS into two at the ribonucleoside adenosine (rA) position, leading to the disruption of the duplex structure. This Pb2+-induced conformational change led to the quenching of the fluorescence of thiazole orange, thus forming the basis for the label-free biosensor. Under the optimized conditions, the developed protocol exhibited sensitive determination of Pb2+ with a detection limit of 0.73 nM and a linear range from 10 to 150 nM. The label-free fluorescent approach exhibited excellent selectivity, strong selectivity, and satisfactory analysis of a drinking water standard reference material and spiked river and tap water samples. Taking the advantage of the structure-switching 8–17 DNAzyme and the fluorescent intercalator of nucleic acids, this label-free sensor provides a new approach for routine screening of heavy metals based upon the DNAzyme.
研究领域:
分析化学
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环境科学
·
生物化学
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DOI
高影响因子
JOURNAL OF FOOD PROCESS ENGINEERING
·
2024
·Vol. 47
·期 6
·e14654
·
IF 2.7
Chengquan Wang,Chengdong Gu,yanna Rong,Xin Zhao,Lu Qian,Mengting Liu,Xingyi Huang,Jing Qian
In this work, a paper-based electrochemical aptamer sensor was developed for the detection of aflatoxin B1 (AFB1) using a combination of MXene–Ti 3 C 2 T x and nucleic acid aptamers. The prepared single-layer or few-layer MXene suspension is suction-filtered onto MXene paper, which is cut to prepare MXene electrodes. To accomplish AFB1 specific detection, an amino-labeled AFB1 aptamer is mounted on the surface of the carboxy-functionalized MXene electrode. When AFB1 is present, it particularly binds to the aptamer to form a 3D structure, reducing the efficiency of electron transmission on the sensor surface. The difference in impedance signal change at the electrode/electrolyte interface is used to quantify AFB1. The results indicated that the detection range is 0.05–100 ng/mL, the detection limit is 0.04 ng/mL, and the recovery rate of AFB1 in corn samples is 97.8%–111.52% with the optimal detection conditions. The MXene paper-based label-free aptasensor is versatile and can detect different targets by simply swapping out the aptamers of different targets. The sensor also has a wide range of applications in food analysis and environmental testing. Practical applications A paper-based electrochemical aptamer sensor was developed to detect aflatoxin B1 using a combination of MXene–Ti 3 C 2 T x and nucleic acid aptamers.The design is based on the preparation of MXene electrodes by pumping and filtering monolayer or multilayer MXene suspensions onto MXene paper and cutting.The MXene paper-based label-free aptamer sensor was designed to be versatile, allowing the detection of different targets by simply replacing the aptamer with one from a different targets.
研究领域:
食品安全
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环境科学
·
生物传感技术
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2021
·
IF 6.558
Zhe Qiao,Zilian Jiang,Qiufen Luo,Hongfang Zhang,Jianbin Zheng
Labeling with redox reporter is often required in developing electrochemical bioassay for most proteins or nucleic acid biomarkers. Herein, a label-free ratiometric immunosensing platform is firstly developed by integrating the antibody-conjugated nanochannels with a smart modified electrode . The electrode modifier is the composite of C 60 , tetraoctylammonium bromide (TOA + ) and Prussian blue (PB). Cyclic voltammograms of the ultimate C 60 -TOA + /PB modified electrode exhibited two pairs of peaks at 0.15 V and −0.13 V, ascribing to the redox of PB and C 60 , respectively. With the addition of K 3 [Fe(CN) 6 ] in the electrolyte solution , the peaks of PB decreased due to the adsorption of [Fe(CN) 6 ] 3− while the peaks of C 60 increased because of the formation of the ternary complex (TC) C 60 -TOA + -[Fe(CN) 6 ] 3− . As a result, the peak current ratio I PB / I TC decreased gradually with the increment of the concentration of [Fe(CN) 6 ] 3− . For the nanochannels-based immunosensing platform, the steric hindrance of the bioconjugated nanochannels varied with the loading amount of the target CA125, and thus [Fe(CN) 6 ] 3− passing through the channels was quantitatively affected. And the higher CA125 level was, the less [Fe(CN) 6 ] 3− concentration was. And thus, the ratio I PB / I TC monitored at the C 60 -TOA + /PB modified electrode increased with the increase of the concentration of CA125. The ratiometric immunoassay featured a linear calibration range from 1.0 U mL −1 to 100 U mL −1 with a low detection limit of 0.86 U mL −1 . In addition, the ratiometric immunosensing platform demonstrated good specificity and stability as well as acceptable accuracy in overcoming the effect of electrode passivation which was an inherent problem of electroanalysis.
研究领域:
生物传感器
·
医学检测
·
电化学分析
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DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 40
·24628-24632
·
IF 3.108
Jiaona Xu,Chunying Wei
A novel, label-free fluorescence detection method was proposed for the formation of the G-quadruplex DNAs based on placing two DNA-Ag NCs together to light-up fluorescence. Herein, we designed two tailored DNA sequences noted as target DNA (abbreviated as T-DNA) and complementary DNA (abbreviated as C-DNA), respectively. T-DNA contains two cytosine-rich sequences at the 3′- and 5′-end responsible for Ag NCs synthesis, together with the guanine-rich (G-rich) DNA sequence in the middle segment. C-DNA was designed completely complementary to the G-rich segment of the T-DNA. Provided that the middle G-rich oligonucleotide of T-DNA folds into G-quadruplex in the presence of monovalent cations, the located at 3′ and 5′ terminuses two darkish DNA-Ag NCs approximate, leading to the enhanced fluorescence signal readout. Upon addition of the C-DNA, the G-quadruplex structure is unfolded and the two DNA-Ag NCs are separated, then the fluorescence signal is quenched. On the contrary, when the G-rich oligonucleotide with mutational bases failed to form the G-quadruplex, the fluorescence signal decreased clearly. This design allowed specific and general detection of the formation of diverse G-quadruplexes with easy operation and low cost. We believed that the proposed approach laid a foundation for the researchers in bioimaging, pharmacology, diagnostics, and other fields.
研究领域:
生物化学
·
分子生物学
·
分析化学
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DOI
高影响因子
SENSORS
·
2018
·Vol. 18
·期 10
·3281
·
IF 2.475
Jingjing Zhang,Chunzheng Yang,Chaoqun Niu,Chen Liu,Xuepin Cai,Jie Du,Yong Chen
In this study, a label-free fluorescent, enzyme-free, simple, highly sensitive AND logic gate aptasensor was developed for the detection of adenosine triphosphate (ATP). Double-stranded deoxyribonucleic acid (DNA) with cohesive ends was attached to graphene oxide (GO) to form an aptasensor probe. ATP and single-stranded DNA were used as input signals. Fluorescence intensity of PicoGreen dye was used as an output signal. The biosensor-related performances, including the logic gate construction, reaction time, linearity, sensitivity, and specificity, were investigated and the results showed that an AND logic gate was successfully constructed. The ATP detection range was found to be 20 to 400 nM (R2= 0.9943) with limit of detection (LOD) of 142.6 pM, and the sensitivity range was 1.846 × 106to 2.988 × 106M−1. This method for the detection of ATP has the characteristics of being simple, low cost, and highly sensitive.Keywords:ATP detection;label-free fluorescence;enzyme-free;graphene oxide;logic gate
研究领域:
生物化学
·
分子生物学
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DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2023
·
IF 6.2
Jie Xiang,Junyi Zhang,Lei Liao,Bingying Jiang,Ruo Yuan,Yun Xiang
The sensitive detection of ten-eleven translocation (TET) dioxygenase is of significance for understanding the demethylation mechanism of 5-methylocytosine (5mC), which is responsible for a wide range of biological functions that can affect gene expression in eukaryotic species. Here, a non-label and sensitive fluorescence biosensing method for TET assay using TET1 as the model target molecule is established on the basis of target-triggered Mg 2+ -dependent DNAzyme and catalytic hairpin assembly (CHA)-mediated multiple signal amplification cascades. 5mC sites in the hairpin DNA probe are first oxidized by TET1 into 5-carboxycytosine, which are further reduced by pyridine borane into dihydrouracil , followed by its recognition and cleavage by the USER enzyme to liberate active DNAzyme and G-quadruplex sequences from the probe. The DNAzyme further cyclically cleaves the substrate hairpins to trigger subsequent CHA reaction and DNAzyme cleavage cycles for yielding many G-quadruplex strands. Thioflavin T dye then intercalates into G-quadruplexes to cause a magnificent increase of fluorescence for high sensitivity assay of TET1 with 47 fM detection limit. And, application of this method for TET1 monitoring in diluted serum has also been confirmed.
研究领域:
生物化学
·
分子生物学
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DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 16
·6074
·
IF 4.6
Fang Li,Shuyue Xiong,Pei Zhao,Panpan Dong,Zijian Wu
Quantitative detection of veterinary drug residues in animal-derived food is of great significance. In this work, a simple and label-free electrochemical aptasensor for the highly sensitive detection of chloramphenicol (CAP) in milk was successfully developed based on a new biosensing method, where the single- or few-layer Ti3C2MXene nanosheets functionalized via the specific aptamer by self-assembly were used as electrode modifiers for a glassy carbon electrode (aptamer/Ti3C2MXene/GCE). Differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscope (AFM), and so on were utilized for electrochemical and morphological characterization. Under the optimized conditions, the constructed aptasensor exhibited excellent performance with a wider linearity to CAP in the range from 10 fM to 1 μM and a low detection limit of 1 fM. Aptamer/Ti3C2MXene/GCE demonstrated remarkable selectivity over other potentially interfering antibiotics, as well as exceptional reproducibility and stability. In addition, the aptasensor was successfully applied to determine CAP in milk with acceptable recovery values of 96.13% to 108.15% and relative standard deviations below 9%. Therefore, the proposed electrochemical aptasensor is an excellent alternative for determining CAP in food samples.Keywords:label-free;electrochemical aptasensor;chloramphenicol;Ti3C2MXene nanosheets
研究领域:
分析化学
·
食品安全
·
电化学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Miaomiao Li,Xiuying Peng,Yujie Han,Lifang Fan,Zhiguang Liu,Yujing Guo
MXenes are attractive for various biosensors owning to their tunable versatile properties. Herein, Ti 3 C 2 nanosheets (Ti 3 C 2 NSs) were found to possess intrinsic peroxidase-like activity, and which could be enhanced by single-stranded DNA (ssDNA) adsorbed on the nanosheets. Hence, a simple label-free sensing strategy was developed for colorimetric detection of biomolecules, based on Ti 3 C 2 NSs as a peroxidase mimic enzyme and ssDNA aptamer as an enzymatic activity enhancement factor along with a recognition substance for the target. In the presence of target biomolecules, the aptamers were desorbed from Ti 3 C 2 NSs due to the specific binding of targets to aptamers, thus bringing about the decrease of catalytic activity. Thrombin (TB) as the model was determined by this constructed biosensor with a linear range of 1.0 × 10 −11 to 1.0 × 10 −8 M, and evaluated subsequently in the real blood samples with satisfactory results. This work highlights Ti 3 C 2 MXenes as a nanomaterial mimic enzyme (called nanozyme) for monitoring biomolecules by target-specific recognition strategy.
研究领域:
生物传感
·
材料科学
·
医学检测
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DOI
高影响因子
危险品化学品经营许可证（带存储）