ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2019
·Vol. 411
·期 11
·2405-2414
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IF 3.286
Wang Chengke,Tan Rong,Li Jiangyu,Zhang Zexiang
In this paper, a fluorescent method was developed for ochratoxin A (OTA) detection that uses iron-doped porous carbon (MPC) and aptamer-functionalized nitrogen-doped graphene quantum dots (NGQDs-Apt) as probes. In this method, the adsorbance of the NGQDs-Apt on the MPC due to a π–π interaction between the aptamer and the MPC results in the quenching of the fluorescence of the NGQDs-Apt. However, since OTA interacts strongly with the aptamer, the presence of OTA leads to the detachment of the NGQDs-Apt from the MPC, resulting in the resumption of fluorescence from the NGQDs-Apt. When exonuclease I (Exo I) is also added to the solution, this exonuclease specifically digests the aptamer, leading to the release of the OTA back into the solution. This free OTA then interacts with another MPC–NGQDs-Apt system, inducing the release of more NGQDs into the solution, which enhances the fluorescent intensity compared to that of the system with no Exo I. Utilizing this behavior of OTA in the presence of NGQDs-Apt, it was possible to detect concentrations of OTA ranging from 10 to 5000 nM, with a limit of detection of 2.28 nM. Our method was tested by applying it to the detection of OTA in wheat and corn samples. This method has four advantages: (1) the magnetic porous carbon is easy to prepare, its porosity enhances its loading capacity for NGQDs, it highly efficiently quenches the fluorescence of the NGQDs, and its magnetic properties facilitate the separation of the MPC from other species in solution; (2) applying double magnetic separation decreases the background signal; (3) Exo I digests the free aptamer effectively, which allows the resulting free OTA to induce the release of more NGQDs-Apt, ultimately enhancing the fluorescent signal; and (4) the proposed method presented high sensitivity and a wide linear detection range. This method may prove helpful in food safety analysis and new biosensor development (achieved by using different aptamer sequences to that used in the present work).
Exonuclease I (Exo I)-assisted fluorescent method for ochratoxin A (OTA) detection using magnetic porous carbon (MPC), nitrogen-doped graphene quantum dots (NGQDs), and double magnetic separation
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2019
·
IF 6.361
Liwang Liu,Hong Li,Zirui Liu,Ya-Hong Xie
Colloidal quantum dots (QDs) have attracted a great amount of attention for their appealing optoelectronic properties. In this work, the CuInS 2 (CIS)/ZnS core/shell QDs based on 4.3 nm cores with various layers of ZnS shell (0 to 10) were synthesized. With the sequential growth of a ZnS shell over a CIS core, the band alignment of core/shell QDs converts from a type I to quasi-type II structure. This conversion prolongs the carrier lifetime and affects the electron transfer rate ( K et ) and electron transfer efficiency ( η ET ). A comparative study indicates that the photovoltaic performance of CIS based QDSCs can be markedly improved by optimizing the layers of ZnS shell. The highest photo conversion efficiency (PCE) of 2.07% is obtained at optimum ZnS thickness of about 1.55 nm. These results show tuning the thickness of shell to change the band alignment is an effective strategy to manipulate the carriers transportation behaviors and thus affect the PCE of CIS-based optoelectronic devices.
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Nanomaterials
·
2019
·Vol. 9
·期 2
·172
·
IF 4.034
Xinyue Lao,Xiyu Li,Hans Ågren,Guanying Chen
Although all-inorganic CsPbX3(X = Cl, Br, I) perovskite quantum dots (PQDs) have evoked exciting new opportunities for optoelectronic applications due to their remarkable optical properties, their emission color tunability has not been investigated to any appreciable extent. In this work, double/triple CsPbX3perovskite quantum dots with precise ratios of Cl/Br or Br/I are synthesized and their luminescence (410–700 nm) is explored. A group of down-converted CsPbX3(X = Cl, Br, I) perovskite quantum dot light-emitting diode (LED) devices were constructed to demonstrate the potential use of such double/triple-halide CsPbX3perovskite quantum dots with full-spectrum luminescence. Based on density functional theory, we theoretically explored the properties of CsPbX3with double/triple anion atoms. The calculated band gaps provided strong support that the full-spectrum luminescence (410–700 nm) of double/triple CsPbX3can be realized with the change of the mixed-halide ratios, and hence that such PQDs are of potential use in optoelectronic devices.Keywords:perovskite quantum dots;light-emitting diode;density functional theory;band gap
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BIORESOURCE TECHNOLOGY
·
2018
·
IF 5.807
Jian Du,Xiu Zhang,Xuezhi Li,Jian Zhao,Guodong Liu,Baoyu Gao,Yinbo Qu
Commercial cellulase preparations for lignocellulose bioconversion are mainly produced by the fungus Trichoderma reesei . The maximum cellulose conversion of T. reesei cellulase mixture was 15%–20% higher than that of Penicillium oxalicum in the hydrolysis of corncob residue and Avicel. Nevertheless, both preparations hydrolyzed more than 92% of cellulose in NaOH-mercerized Avicel. When added to Avicel hydrolysis residue that was less reactive to P. oxalicum cellulases, cellobiohydrolase I (CBH I) from T. reesei resulted in a higher cellulose conversion than its homologous proteins from P. oxalicum and Aspergillus niger at the same protein loadings. Further domain exchange experiment attributed the high hydrolytic efficiency of T. reesei CBH I to its inter-domain linker and cellulose-binding domain. The results in part explained the superior performance of T. reesei cellulases on the degradation of native crystalline cellulose, and highlighted the important role of cellulose-binding region in determining the degree of hydrolysis by cellulases.
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SENSORS AND ACTUATORS B-CHEMICAL
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2013
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IF 3.535
Ning Yu Chen,Hong Fei Li,Zhong Feng Gao,Fei Qu,Nian Bing Li,Hong Qun Luo
In this work, fluorescence resonance energy transfer (FRET) between Sudan I–IV and polyethyleneimine-capped silver nanoclusters (PEI-AgNCs), which are smaller than the critical size for electronic energy quantization (∼2 nm), is investigated and subsequently utilized for Sudan I–IV sensing in ethanol. The PEI-AgNCs exhibit strong blue fluorescence when excited at 375 nm, and the fluorescence would be greatly enhanced when the nanoclusters are dissolved in given organic solvents, especially in n-propanol and ethanol. The characteristic emission peak of Ag nanoclusters is centered at 450 nm in ethanol. Upon addition of Sudan dyes, the fluorescence of PEI-AgNCs can be efficiently quenched. The fluorescence quenching efficiency was proportional to the concentration of Sudan dyes. Thus, precise quantification of Sudan I–IV can be made. Under optimum conditions, this fluorescence method shows a wide linear range of 0.4–25 μM Sudan I, 0.4–30 μM Sudan II, 0.2–20 μM Sudan III, and 0.2–25 μM Sudan IV, with the corresponding detection limits (3 σ /slope) of 11.0, 12.2, 8.0, and 7.6 nM, respectively. Using commercial chilli powder as a model sample, detection of Sudan I–IV could be made with satisfactory results. Furthermore, the sensing mechanism for detection of Sudan dyes is discussed.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xiaojuan Niu,Lian Xia,Yue Tang,Zhen Wu,Keya Liu,Yuangen Wu
Fumonisin B1 (FB1) is a secondary metabolite produced by Fusariums , which principally contaminates grains and their products, causing pathological and physiological toxicity to humans and animals. Herein, a convenient and rapid colorimetric strategy for FB1 detection was established based on the inhibition effect of FB1 on Ag(I)–3,3′,5,5′-tetramethylbenzidine (TMB) catalytic system. It was found that FB1 can hinder the generation of superoxide anions (O 2 · - ) in the sensing solution, leading to a significant reduction of oxTMB production. Thus, the absorbance and color change of the solution are directly related to the concentration of FB1. Under optimal experimental conditions, there is a satisfactory sensitivity with a limit of detection (LOD) as low as 1.77 ng·mL −1 . Moreover, such colorimetric strategy has outstanding selectivity, and can be used for the detection of FB1 residues in corn and infant rice flour, with a recovery rate of 90.15–109.74 %. Especially, the RGB values corresponding to chromogenic solutions with different FB1 contents can be easily recognized by a smartphone for qualitative and quantitative analysis of FB1. The colorimetric sensing strategy does not require the preparation of nanomaterial, providing a low-cost and promising analysis strategy for FB1 detection.
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COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Tingting Zhang,Jin He,Ning Xu,Wang Yin,Dongli Liu,Chang Liu,Meidong Lang
During the service life of thermoset matrix fiber-reinforced polymer composites, they are susceptible to structural damage such as delamination after low-velocity impacts, thereby affecting their mechanical properties and structural integrity. Therefore, this paper adjusted the properties of polydicyclopentadiene matrix through copolymerization and incorporation of elastomers to obtain modified polydicyclopentadiene/glass fiber composites with improved interlaminar fracture toughness and impact resistance without significantly sacrificing rigidity. The results indicated that compared to polydicyclopentadiene/glass fiber, the G Ⅰ,R increased from 2.61 kJ/m 2 to 4.33 kJ/m 2 and the G ⅡC increased from 3.04 kJ/m 2 to 4.07 kJ/m 2 by incorporating 10 wt% cyclooctadiene and 2 phr styrene-ethylene-butylene-styrene. The energy dissipation mechanisms leading to these improvements included matrix ductile fracture, shear yielding, particle crack bridging, particle fracture, and particle debonding. Additionally, compared to polydicyclopentadiene/glass fiber, the damage area decreased under drop weight impact by incorporating styrene-ethylene-butylene-styrene. Moreover, compared with epoxy/glass fiber composites, modified polydicyclopentadiene/glass fiber composites demonstrated superior interlaminar fracture toughness and impact resistance. The interlaminar fracture toughness of modified polydicyclopentadiene/glass fiber was comparable to that of thermoplastic matrix composites. This study provided a significant method for enhancing the interlaminar toughness and impact resistance of polydicyclopentadiene/glass fiber composites by adjusting the matrix toughness.
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INTERNATIONAL IMMUNOPHARMACOLOGY
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2025
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IF 4.7
Zhifeng Geng,Guoyi Deng,Ziyu Wang,Xin Xu,Xiaojiao Yin,Sen Zhang,Jiale Shao,Jiyue Wen
Astrocytes may fail to perform their neuroprotective roles against cerebral ischemia/reperfusion (I/R) injury due to phenotypic transformation. We aimed to demonstrate the distinct roles of A1 astrocytes and A2 astrocytes on the blood-brain barrier (BBB) injury following cerebral I/R, and explore whether H 2 S-mediated A2 astrocytes polarization protects against BBB injury via inhibiting ROCK/NF-κB pathway. The mice cerebral I/R model and the oxygen-glucose deprivation/re‑oxygenation (OGD/R) model of astrocytes were used in present study. Cerebral I/R-induced BBB injury is evidenced by increased EB dye leakage and reduced expressions of ZO-1 and occludin in mice hippocampal tissues. We found that H 2 S-mediated A2 polarization and lipopolysaccharide (LPS)-induced polarization of A1 astrocytes respectively display beneficial and harmful role in BBB injury. Besides, harmful roles of A1 astrocytes in BBB injury can be reduced by H 2 S. Additionally, A1 astrocytes exhibit excessive activation of NF-κB and enhanced expressions of MMP9 and AQP4, which can be inhibited by H 2 S. Moreover, H 2 S-mediated polarization of A2 astrocyte displays enhanced phosphorylation and nuclear translocation of STAT3 and reduced expressions of MMP9 and AQP4. Importantly, ROCK inhibitor Fasudil likewise inhibits the activation of NF-κB and promotes STAT3 activation in OGD/R astrocytes, and NF-κB inhibitor BAY11–7082 reduces the expressions of MMP9 and AQP4 in OGD/R astrocytes. In conclusion, H 2 S-mediated polarization of A2 astrocyte protects against BBB injury following cerebral I/R, the mechanisms may be related to inhibition of ROCK/NF-κB pathway, and activation of STAT3.
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TALANTA
·
2024
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IF 5.6
Xiaolun Peng,Ruijie Xu,Fan Yu,Junhui Xu,Yazhen Wang,Shengfu Wang
Considering the close association between cardiac troponin I (cTnI) level and various cardiovascular diseases, it becomes essential to explore sensitive and accurate detection methods for monitoring their levels in the early stages of disease. In this work, a magnetic dual-aptamer electrochemical sensor for cTnI detection was constructed in the first utilizing MOF-on-MOF-derived electrocatalyst as a signal amplifier in collaboration with high-efficient separation of magnetic beads (MBs). Employing zeolitic imidazolate framework-67 (ZIF-67) with high surface area as host MOF, MOF-on-MOF heterostructure (ZIF-67@PBA) was facilely prepared by in-situ growth of conductive prussian blue analogue (PBA) as guest MOF onto the surface of ZIF-67 with a simple ion-exchange method. After low-temperature calcination, N doped derived electrocatalyst (N-ZIF-67@PBA) was obtained with intact skeletons and pore structures of MOFs. This not only integrated bimetallic active centers with various valence states and diversiform nanostructures of dual MOF, but endowed N-ZIF-67@PBA 8.3-fold increase of electrocatalytic activity for catalytic amplification. Further using aptamer-modified MBs as capture carriers for recognizing and separating cTnI from complex samples with high specificity, the magnetic dual-aptamer sensor successfully achieved the sensitive detection of cTnI with a low detection limit of 0.31 fg/mL. This work provided a new viewpoint on the use of MOF-on-MOF-derived electrocatalyst for ultrasensitive electrochemical sensing analysis.
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Journal of Energy Chemistry
·
2023
·
IF 13.1
Han Yan,Ruifeng Song,Ruonan Xu,Shulin Li,Qiaoquan Lin,Xinlin Yan,Zhenyu Wang,Chuang Yu,Long Zhang
The (electro)chemical stability and Li dendrite suppression capability of sulfide solid electrolytes (SEs) need further improvement for developing all-solid-state Li batteries (ASSLBs). Here, we report advanced halogen-rich argyrodites via I and Cl co-occupation on the crystal lattice. Notably, a proper I content forms a single phase, whereas an excessive I causes precipitation of two argyrodite phases like a superlattice structure. The resultant synergistic effect of the optimized composition allows to gain high ionic conductivities at room temperature and −20 °C, and enhances the (electro)chemical stability against Li and Li dendrite suppression capability. The Li|argyrodite interface is very sensitive to the ratio of I and Cl. A LiCl- and LiI-rich double-layer interface is observed from the cell using the SE with optimized composition, whereas too high I content forms only a single interface layer with a mixture of LiI and LiCl. This double-layer interface is found to effectively mitigate the Li/SE reaction. The proper designed argyrodite enables ASSLBs to achieve good electrochemical properties at a broad temperature range regardless of the electrode materials. This co-occupation strategy provides a novel exploration for advanced halogen-rich argyrodite system.
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Advanced Composites and Hybrid Materials
·
2024
·Vol. 7
·期 3
·1-16
·
IF 23.2
Wang Hengda,Yusufu Yalikun,Wang Lanlan,Gan Jian,Zhang Meng,Gu Jiayu,Lan Kai,Wang Peng,Huang Caoxing
Silk fibroin (SF), an innovative bioactive material widely used in tissue engineering, is commonly employed to construct biological scaffolds. Conventional approaches for fabricating water-insoluble SF-based films, such as evaporative dehydration and induced annealing with organic solvents, often result in membranes dominated by silk II structures with poor ductility and intricate preparation processes. In this study, inspired by the self-assembly behavior observed in SF solution during dialysis, we developed a unidirectional nanopore dehydration (UND) method to prepare SF-based membranes (SFM U ) dominated by silk I structures. The SF solution underwent direct dehydration through UND, yielding enhanced water stability. Furthermore, to enhance the overall properties of SFM U and apply it to the field of bone tissue engineering, biocompatible iron oxide nanoparticles (IONPs) were incorporated into SFM U , leading to the creation of three types of SFM U -IONPs by varying the added IONP amounts. The results demonstrated that SFM U -IONPs formed water-insoluble silk I structures with a lower elastic modulus, and the addition of IONPs endowed neat SFM U with improved structural order, porosity, and mechanical properties. Additionally, SFM U -IONPs demonstrated exceptional biocompatibility towards pre-osteoblast cell line MC3T3-E1 as evidenced by their non-toxic effects on cell viability and attachment. Taken together, SFM U -IONPs with enhanced properties could serve as promising repair composite membranes for bone regeneration in clinical applications. Graphical Abstract
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Chaoyi Guo,Jie Jiang,Zhihua Zhu,Jinjin Li,Ling Zhao,Zhenhao Xi
Semi-aromatic nylon MXD6 shows superior mechanical strength and gas barrier properties. To improve its toughness and get sight into its excellent properties, a series of poly( m -xylylene adipamide-co-isophthalamide) (MXD6/I) random copolyamides were synthesized using adipic acid, isophthalic acid (IPA) and m -xylylene diamine as monomers via direct melt polycondensation. The effect of IPA content on the thermal, crystallization, heat resistant, mechanical, and barrier properties of the copolyamides were systematically investigated. The results showed that the increase of IPA content from 0 to 12 mol% resulted in a decrease in the melting point of the copolyamides from 238 to 217°C but the glass transition temperature ( T g ) increased from 88 to 105°C. Correspondingly, the Vicat softening temperature decreased from 199.2 to 172.5°C. The crystallization rate of the copolyamides significantly decreased with the increase of the IPA content. The copolyamides had improved elongation and rupture energy and decent oxygen barrier properties with the introduction of IPA. It is expected that this study would guide design of MXD6 macromolecular chain structure to prepare high-performance MXD6 materials.
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