Food Analytical Methods
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2021
·Vol. 14
·期 6
·1121-1132
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IF 3.366
Sun Chao,Gao Xiaoqi,Wang Lei,Zhou Nan
Reactive nitrogen species (RNS) are vital signaling molecules involved in most physiological and pathological processes. Within RNS, nitric oxide (NO) and its metabolite nitrite (NO 2 − ) have been widely applied in medicinal, food, and environmental fields. However, at present, the methods of detecting RNS by fluorescence quenching through chemical reactions have disadvantages, such as long reaction time and weak anti-interference ability. In response to these existing problems, we have developed a novel fluorescent probe, namely, carbon quantum dots (CDs) that are passivated by benzylamine. The obtained CDs (named B-CDs) possess excellent down- and upconversion properties. In particular, upconversion is used to sensitively and selectively measure NO and NO 2 − under different pH conditions in aqueous media via two different mechanisms (static and dynamic quenching). At pH 7.4, the nanomolar concentration of NO, produced from sodium nitroprusside (SNP) in a concentration-dependent manner, can be rapidly detected with a correlation coefficient ( R 2 ) greater than 0.99. Similarly, the quantitative detection of NO 2 − at pH 1.6 also shows a good linear relationship with a linear range of 0–14 μM, and a limit of detection (LOD) that is as low as 43 nM and 0.65 μM at excitation wavelengths of 800 nm and 375 nm, respectively. Notably, this probe stands out due to its extremely short response time and outstanding selectivity and anti-interference ability against a variety of common interfering substances, while realizing the fast and highly selective and sensitive detection of NO and NO 2 − . Finally, this probe has been successfully applied to the sensing of NO in fetal bovine serum (FBS) samples and NO 2 − in milk and tap water samples. Graphical abstract
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BIOMACROMOLECULES
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2020
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IF 6.092
Zhiwei Wang,Min Lin,Colin Bonduelle,Rongye Li,Zhekun Shi,Chenhui Zhu,Sébastien Lecommandoux,Zhibo Li,Jing Sun
Delicate control over architectures via crystallization-driven self-assembly (CDSA) in aqueous solution, particularly combined with external stimuli, is rare and challenging. Here, we report a stepwise CDSA process thermally initiated from amphiphilic poly(N-allylglycine)-b-poly(N-octylglycine) (PNAG-b-PNOG) conjugated with thiol-terminated triethylene glycol monomethyl ethers ((PNAG-g-EG3)-b-PNOG) in aqueous solution. The diblock copolymers show a reversible thermoresponsive behavior with nearly identical cloud points in both heating and cooling runs. In contrast, the morphology transition of the assemblies is irreversible upon a heating–cooling cycle because of the presence of a confined domain arising from crystalline PNOG, which allows for the achievement of different nanostructured assemblies by the same polymer. We demonstrated that the thermoresponsive property of PNAG-g-EG3 initiates assembly kinetically that is subsequently promoted by crystallization of PNOG thermodynamically. The irreversible morphology transition behavior provides a convenient platform for comparing the cellular uptake efficiency of nanostructured assemblies with various morphologies that are otherwise similar.
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高影响因子
Biomaterials Science
·
2020
·Vol. 8
·期 24
·6969-6977
·
IF 6.183
Bo Zhang,Min Li,Min Lin,Xuan Yang,Jing Sun
Bioinspired polypeptoids show great potential in many applications. Here, we report a convenient approach to synthesize a novel type of polypeptoid containing both sulfonium and oligo(ethylene glycol) (OEG) moieties by ring-opening polymerization (ROP) and a post-modification strategy. Three types of epoxides with (OEG)n (n = 1–3) groups are involved to offer various functionalities. The obtained polypeptoid sulfonium salts show positive ζ potential, irrespective of the solution pH and the degree of polymerization (DP). We demonstrate that the polypeptoids exhibit excellent antibacterial activity against Staphylococcus aureus (S. aureus) with MIC (minimal inhibitory concentration) in the range of 3.9–7.8 μg mL−1. In addition, the polypeptoids have a low hemolysis property and good in vitro biocompatibility. Remarkably, the as-prepared polypeptoids show rapid and potent antibacterial activity within 5 min. These features suggest that the obtained polypeptoids offer great potential for antimicrobial agents.
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高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Wei Luo,Jiagui Hu,Jiapeng Lu,Huili Zhang,Xiaoping Wang,Yuantao Liu,Liqing Dong,Xiaobin Yu
ω-transaminase can mediate the asymmetric synthesis of chiral amines from aldehydes and ketones , which has important value in the synthesis of pharmaceutical intermediates. A novel ω-transaminase derived from Paracoccus pantotrophus ( Pp TA) was obtained and cloned in E. coli BL21(DE3) for expression. The enzyme has high activity for 2-ketobutyric acid and benzylamine , as well as for aromatic compounds with side chains longer than ethyl aliphatic hydrocarbons . Molecular simulation showed that the S-pocket in the active center is larger than those of other ω-transaminases. Thereafter, a whole-cell catalytic system was designed to prepare l -2-aminobutyric acid by cascading Pp TA and other enzymes. By using several strategies (regulation of RBS intensity, by-product decomposition and cofactor self-sufficiency), whole-cell cascade biocatalysis showed a high ee value (> 99%) and high yield (71%) in one pot reaction . This study therefore proposes an efficient biocatalyst for the synthesis of unnatural amino acids with the participation of ω-transaminase.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Haijing Gao,Yajie Chen,Huali Li,Fangfang Zhang,Guohui Tian
Copper-based chalcogenides have been paid intensive attention as alternate photothermal catalysts for solar energy conversion. Despite considerable progress of copper sulfides nanostructure fabrication, combining independent copper sulfides polymorphs with various stoichiometries by forming heterojunction is still challenging. Herein, unique hierarchical nanosheet-assembled Cu 7 S 4 -Cu 9 S 8 heterostructure hollow cubes with remarkable photothermal aerobic oxidation activity were prepared by a facile onepot chemical transformation route using Cu 2 O cubes as sacrificial template for the first time. In this reaction system, the introduction of proper sulfur source thioacetamide and moderate alkaline conditions plays a crucial role in phase transformation, and through tunning the reaction time, a series of Cu 7 S 4 , Cu 7 S 4 -Cu 9 S 8 , and Cu 9 S 8 can be selectively prepared. Furthermore, the Cu 7 S 4 -Cu 9 S 8 polymorphic heterostructure hollow cubes exhibit significantly enhanced photothermal aerobic oxidation performance of amines to the corresponding imines compared with the individual Cu 7 S 4 and Cu 9 S 8 in both N , N -dimethylformamide and acetonitrile solvent medium. Our results indicated that the strong near-infrared plasmonic absorption of Cu 7 S 4 -Cu 9 S 8 facilitated hot carrier transport between Cu 7 S 4 and Cu 9 S 8 , which subsequently promoted the catalytic reactions. Especially after uniform load of Au-Pt alloy nanoparticles, the photothermal aerobic oxidation activity was further enhanced due to their boosted synergistic local coupling enhancement effect between distinct components in the N , N -dimethylformamide solvent medium. Such enhanced photothermal reaction could effectively promote sunlight utilization in a wide range of photocatalytic reactions.
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RSC Advances
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2019
·Vol. 9
·期 12
·6717-6723
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IF 3.049
Xiuli Dong,Jiayuan Tang,Yan Ren,Xiangming Chen
A novel fluorescence labeling reagent N-acetylhydrazine acridone (AHAD) was designed and synthesized. A highly sensitive high performance liquid chromatography (HPLC) method coupled with fluorescence detection to determine benzaldehyde after derivatization with AHAD was developed. Optimum derivatization was obtained at 40 °C for 30 min with trichloroacetic acid as catalyst. Benzaldehyde derivative was separated on a reversed-phase SB-C18 column in conjunction with a gradient elution and detected by fluorescence detection at excitation and emission wavelengths of 371 nm and 421 nm. The established method exhibited excellent linearity over the injected amount of benzaldehyde of 0.003 to 5 nmol mL−1. The method was successfully applied to the determination of serum semicarbazide-sensitive amine oxidase (SSAO) activity in humans. SSAO is a significant biomarker because serum SSAO activity is elevated in patients with Alzheimer's disease, vascular disorders, heart disease and diabetes mellitus. It was demonstrated that the SSAO activity of the hyperglycemic group (60 ± 4 nmol mL−1 h−1) was significantly higher than that of normal blood sugar group (44 ± 4 nmol mL−1 h−1) with P < 0.05.
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CHEMISTRY OF MATERIALS
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2019
·
IF 10.159
Qin Wang,Jin Li,Xianjun Tu,Hongbo Liu,Miao Shu,Rui Si,Calum T. J. Ferguson,Kai. A. I. Zhang,Run Li
Generation of efficient light-induced charge separation inside the photocatalyst is an essential factor for a high catalytic efficiency. The usual immobilization of metal or metal oxide particles on semiconductor photocatalysts offers an uncontrolled assembly of active sites during the reaction. The introduction of single metal atoms on photocatalysts can lead to extremely high atomic utilization and precise active sites. However, this approach is limited because of the lack of suitable photosensitizers for single atom immobilization. Here, we have designed photocatalytic carbon quantum dots with anchoring sites for single cobalt atoms in a defined Co–N4 structure via facile pyrolysis of vitamin B12. Carbon dots functioned as both light-harvesting antenna and support for the cobalt atom with high atom loadings up to 3.27 wt %. This new photocatalytic material demonstrated enhanced visible light absorption, efficient charge separation, and reduced electrochemical impedance, while single Co atoms acted as the active site with strong oxidative ability. As a result, the photocatalysts showed excellent visible light-promoted photocatalytic efficiency with oxygen evolution rates up to 168 μmol h–1 g–1 via water oxidation, imine formation with high conversion (∼90%) and selectivity (>99%), and complete photodegradation of organic dyes.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
·
IF 14.229
Yu Ding,Bo-Qiang Miao,Shu-Ni Li,Yu-Cheng Jiang,Yan-Yan Liu,Hong-Chang Yao,Yu Chen
In this work, ultra-thin Ni 2 P nanomeshes (1.9 nm thickness) on nickel foam (NF) substrate (denoted as Ni 2 P-UNMs/NF) are successfully achieved through phosphidation treatment using ultra-thin Ni(OH) 2 nanomeshes on NF substrate (denoted as Ni(OH) 2 -UNMs/NF) as reaction precursor. Because of the sufficient active sites in edge of the holes, high specific surface area, porous framework and high conductivity of NF substrate, Ni 2 P-UNMs/NF nanocomposites show the outstanding activity for both hydrogen evolution reaction (HER) and benzylamine oxidation reaction (BOR) in alkaline electrolyte. Importantly, Ni 2 P-UNMs/NF nanocomposites can directly act as a bifunctional electrocatalyst for the electrochemical water-splitting in two electrode system in the presence of benzylamine, which only requires an electrolysis voltage of 1.41 V to achieve the 10 mA cm -2 current density in alkaline electrolyte, accompanying with H 2 production at cathode and value-added benzonitrile production at anode. Obviously, the BOR boosted electrochemical water-splitting provides an energy-saving and cost-competitive H 2 production method.
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高影响因子
CHEMISTRY OF MATERIALS
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2019
·
IF 10.159
Bingquan Jia,Wei Zhao,Du Sun,Linggang Fan,Heliang Yao,Ping Lu,FangFang Xu,Fuqiang Huang
Solution-mediated sequential ion exchange has emerged as a powerful yet simple technique to transform nanoparticulates into a complex architecture. However, the state-of-the-art demonstration of such fine-tailored nanostructures greatly relied on cation exchange reaction because it remains to be a great challenge to apply anion exchange without interfering the original morphology and crystallinity of the target particles. Herein, metal cyanamides with a looser cation sublattice enabled by the quasi-linear [NCN]2– anion units are discovered to be ideal parent compounds to accomplish robust anion exchange reactions. The complete conversion from metal cyanamide nanoparticles to metal chalcogenide nanoparticles (CdNCN to CdS, CdNCN to CdSe, and MnNCN to MnS) is successfully realized by low-temperature reaction in colloidal solution. The nanoparticles retain both the morphology and crystallinity throughout the entire exchange process. In-depth study reveals that the structural similarity in cation packing facilitates the exchange process, and such behavior is independent of the material composition. The quasi-linear structure of the three-atom [NCN]2– anion results in anisotropic lattice spaciousness, which helps bypass the diffusion rate discrepancy and lattice framework collapse commonly encountered in compounds consisting of single-atom anions. This work sheds light on extending the ion exchange reactions as a synthetic toolbox to a much broader library in nanoparticle synthesis.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Ganhua Qiu,Renshan Wang,Fang Han,Xueqin Tao,Yi Xiao,Benxia Li
The remarkable limitations in photocatalysis still remain: low utilization of visible light, poor charge transfer and separation, and insufficient active sites. To address these issues, herein, Au–Bi2WO6 hybrid photocatalysts are synthesized through a one-step solvothermal method, possessing a good combination of plasmonic Au nanoparticles (NPs) and abundant oxygen vacancies (OVs) in the hybrid nanostructures. The Au–Bi2WO6 hybrid photocatalyst with an optimal Au content exhibits outstanding activity and selectivity toward selective oxidation of aromatic amines under visible light, far outperforming pure Bi2WO6 nanostructures. The collaborative contributions of hot charge carriers from Au NPs, photoexcited electron–hole pairs from Bi2WO6, and the OVs for efficient adsorption–activation of molecular O2 result in the enhanced photocatalysis for selective oxidation under visible-light irradiation. This study will motivate the rational construction of metal–semiconductor hybrid photocatalysts with multiple active sites and boost the utilization of solar energy to drive a broad range of organic transformations.
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高影响因子
BIOMACROMOLECULES
·
2018
·
IF 5.738
Chao Xing,Zhekun Shi,Jiliang Tian,Jing Sun,Zhibo Li
Stimuli-responsive polymers have received increasing interest for a variety of applications. Here, we report a series of unique charge-determined thermoresponsive polypeptoids synthesized by a combination of ring-opening polymerization and click chemistry. The LCST-type and UCST-type behavior is mainly dominated by the charge state on the side chain. Further, the phase transition temperature highly depends on the degree of polymerization, the side-chain architecture, the pH value, and so on. The obtained polypeptoid solutions exhibit good stability against temperature and salt concentration. To our knowledge, this report presents the first charge-determined LCST/UCST-type polymer from identical homopolymer backbone that displays a wide range of tunable cloudy points in aqueous media. We propose the hydrogen-bonding interaction plays a critical part on the solution behavior. These features make polypeptoids ideal candidates for highly designable stimuli-responsive polymeric materials.
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ACS Applied Energy Materials
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2018
·
IF 0
Xiaolei Li,Bochao Li,Jianhui Chang,Bin Ding,Shuaizhi Zheng,Yiwei Wu,Junliang Yang,Guanjun Yang,Xiangli Zhong,Jinbin Wang
The toxicity and the instability of lead-based perovskites might eventually hamper the commercialization of perovskite solar cells. Here, we present the optoelectronic properties and stability of a two-dimensional layered (C6H5CH2NH3)2CuBr4 perovskite. This material has a low Eg of 1.81 eV and high absorption coefficient of ∼1 × 105 cm–1 at the most intensive absorption at 539 nm, implying that it is suitable for light-harvesting in thin film solar cells, especially in tandem solar cells. Furthermore, X-ray diffraction (XRD), ultraviolet–visible (UV–vis) absorption spectra, and thermogravimetric analysis (TGA) confirm the high stability toward humidity, heat, and ultraviolet light. Initial studies produce a mesoscopic solar cell with a power conversion efficiency of 0.2%. Our work may offer some useful inspiration for the further investigation of environment-friendly and stable organic–inorganic perovskite photovoltaic materials.
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