TALANTA
·
2014
·
IF 3.511
Xiaohua Jiang,Huimin Zhang,Jun Wu,Xiang Yang,Jingwei Shao,Yujing Lu,Bin Qiu,Zhenyu Lin,Guonan Chen
In this paper, a novel label-free G-quadruplex DNAzyme sensor has been proposed for colorimetric identification of GMO using CaMV 35S promoter sequence as the target. The binary probes can fold into G-quadruplex structure in the presence of DNA-T (Target DNA) and then combine with hemin to form a DNAzyme resembling horseradish peroxidase . The detection system consists of two G-rich probes with 2:2 split mode by using the absorbance and color of ABTS 2− as signal reporter. Upon the addition of a target sequence, two probes both hybridize with target and then their G-rich sequences combine to form a G-quadruplex DNAzyme, and the DNAzyme can catalyze the reaction of ABTS 2− with H 2 O 2 . Then the linear range is from 0.05 to 0.5 μM while detection limit is 5 nM. These results demonstrate that the proposed G-quadruplex DNAzyme method could be used as a simple, sensitive and cost-effective approach for assays of GMO.
研究领域:
生物化学
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分子生物学
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食品科学
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DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Yi-Qing Sun,Yue Cheng,Xue-Bo Yin
Sensitivity, selectivity, visible detection, and rapid response are the main concerns for an analytical method. Herein, we reported a metal–organic framework (MOF)-based ratiometric fluorescence detection strategy for hypochlorous acid (HClO). The MOF was prepared with dual ligands, 2-aminoterephthalic acid (BDC-NH2) and dipicolinic acid (DPA) and Eu3+ ions as a metal node, denoted as Eu-BDC-NH2/DPA. The dual-ligand strategy realized the dual emission for ratiometric sensing and visual detection, adjusted the size and morphology of MOFs to obtain a good dispersion for a rapid response, and provided an amino group for the special recognition of HClO. Thus, the MOF exhibited a dual emission derived from BDC–NH2 and Eu3+ ions at 433 and 621 nm, respectively, under a single excitation at 270 nm. A hydrogen bond forms between an −NH2 group and HClO to weaken the blue fluorescence at 433 nm, while the antenna effect emission from Eu3+ ions kept stable, so ratiometric sensing was realized with an easy-to-differentiate color change for visible detection. The ratiometric sensing showed a self-calibration effect and reduced the background. Thus, the high sensitivity, visual detection, low detection limit (37 nM), and short response time (within 20 s) for the detection of HClO were realized with the MOF as a probe. The analysis of real samples demonstrated the practical application of the MOF for HClO. The introduction of mixed ligands is an effective strategy to regulate the emission behaviors of MOFs for the improved analytical performance.
研究领域:
分析化学
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材料科学
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荧光传感
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产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2025
·Vol. 15
·期 36
·29217-29229
·
IF 4.6
Pengju Ren,Shusheng Luo,Lijuan Wang,Yihan Chi,Yuanyuan Tang
Nanoplastics (NPs) are an emerging contaminant in natural freshwater environments. However, there is a lack of analytical methods for separating and characterizing NPs by particle size, which is essential for analyzing their environmental behavior. Asymmetrical flow field-flow fractionation (AF4) is considered a reliable technique suitable for separating and characterizing the particle size of macromolecules, colloids, and particles. In this work, we report a method for separating and characterizing the size of polystyrene nanoplastics (PS NPs) in freshwater environments using AF4 coupled with MALS and UV-vis detectors. By optimizing the injection volume, mobile phase composition, cross-flow rate, and detector flow rate, we achieved the separation of 50 nm and 100 nm PS NPs within 40 min. The average mass recovery rate reached 88.5%, with relative standard deviations of less than 10% for different indicators in repeated measurements. The R2 value of the linear regression between concentration and UV peak area exceeded 0.99. We applied this method to natural freshwater media and analyzed the particle sizes of particles added to the freshwater media for 0 and 48 hours using dynamic light scattering (DLS). The results revealed that, despite the appearance of a small number of particle aggregates with sizes close to 250 nm in some freshwater media after 48 hours, the optimized AF4 method still effectively separated the majority of the original unaggregated particles. This effective separation demonstrates the practical feasibility of applying the AF4 method to environmental water samples.
研究领域:
环境科学
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分析化学
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纳米技术
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水资源研究
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Fan Wang,Yuqing Wang,Lili Zhang,Ting Zheng,Jun Shen
Two novel cellulose phenylcarbamate derivatives bearing 3,5-dimethylphenylcarbamate substituents at 2,3-positions and 4-(4-(3-(2-benzo[ d ]thiazolyl)ureayl)benzyl)) ( Cel-1 ) or 4-(4-(3–4-(2-benzo[ d ]thiazolyl)phenyl)ureayl)benzyl)) ( Cel-2 ) at 6-position of glucose units were prepared. Their metal ion discrimination properties were then carefully scrutinized using 12 metal ions. Combined the 2,3-dimethylphenylcarbamates with a more bulky benzothiazolyl phenylcarbamate at 6-position, the derivative Cel-2 exhibited excellent recognition ability for both Cu 2+ and Fe 3+ , and achieved high selective detection at extremely low concentrations through fluorescence and UV–visible modes. The limit of detection of Cel-2 for the two metal ions in both modes were 2.0 μM (Cu 2+ ) and 1.0 μM (Fe 3+ ) (in fluorescence mode), 1.3 μM (Cu 2+ ) and 0.7 μM (Fe 3+ ) (in UV–visible mode), respectively, which were much lower than the maximum pollution level for copper ions (20 μM) and iron ions (5.4 μM) in the potable water. In addition, good anti-interference ability of Cel-2 was also observed for specific detection of Cu 2+ /Fe 3+ in the combined system containing other metal ions. It revealed that the obtained regioselectively substituted phenylcarbamate of cellulose possessed powerful performance for efficient detection of Cu 2+ /Fe 3+ in various circumstance via fluorescence and UV–visible modes. Furthermore, Cel-2 was also been prepared into smart ink, presenting its possible potential in the anti-counterfeiting application.
研究领域:
高分子化学
·
分析化学
·
材料科学
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环境监测
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传感器与生物传感器
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金属离子检测
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产品关联
DOI
PubMed
高影响因子
TALANTA
·
2023
·
IF 6.1
Gaozhen Li,Jiashuai Sun,Jiahuan Li,Yaoli Zhang,Jingcheng Huang,Fengling Yue,Haowei Dong,Falan Li,Huihui Xu,Yanyin Guo,Yemin Guo,Xia Sun
In order to achieve a highly sensitive detection of procymidone in vegetables, three paper-based biosensors based on a core biological immune scaffold (CBIS) were developed, which were time-resolved fluorescence immunochromatography strips with Europium (III) oxide (Eu-TRFICS). Goat anti-mouse IgG and europium oxide time-resolved fluorescent microspheres formed secondary fluorescent probes. CBIS was formed by secondary fluorescent probes and procymidone monoclonal antibody (PCM-Ab). The first type of Eu-TRFICS (Eu-TRFICS-(1)) fixed secondary fluorescent probes on a conjugate pad, and PCM-Ab was mixed with a sample solution. The second type of Eu-TRFICS (Eu-TRFICS-(2)) fixed CBIS on the conjugate pad. The third type of Eu-TRFICS (Eu-TRFICS-(3)) was directly mixed CBIS with the sample solution. They solved the problems of steric hindrance of antibody labeling, insufficient exposure of antigen recognition region and easy loss of activity in traditional methods. They realized multi-dimensional labeling and directional coupling. They replaced the loss of antibody activity. And the three types of Eu-TRFICS were compared, among which Eu-TRFICS-(1) was the best detection choice. Antibody usage was reduced by 25% and sensitivity was increased by 3 times. Its detection range was 1–800 ng/mL, the limit of detection (LOD) was 0.12 ng/mL with the visible LOD (vLOD) of 5 ng/mL.
研究领域:
分析化学
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生物传感
·
食品安全
·
环境监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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