MATERIALS CHEMISTRY AND PHYSICS
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2020
·
IF 3.408
Hanjun Zhang,Furong Tao,Yuezhi Cui,Hongtao Wu
Fluorescent conjugated polymers are widely used for trace detection of explosives due to their super-quenching effect. In this work, a hyper-branched conjugated polymer P2 and a linear conjugated polymer P1 were synthesized. Compared with P1, P2 showed the superior sensitivity toward 2,4,6-trinitrophenol (PA). The Stern-Volmer constants ( K sv ) of P2 (1.56 × 10 4 M −1 ) was 2.7 times higher than that of P1 (0.57 × 10 4 M −1 ), and the LODs to PA of P2 (8.8 μM) was 3.2 times lower than that of P1 (24 μM). These data indicated the enhanced super-quenching effect in P2. Due to the electrons transfer among the conjugated backbone of polymer, the super-quenching effect of P1 with one-dimensional (1D) configuration may be defined as “length quenching”, while that of P2 with two-dimensional (2D) configuration can be defined as “Area quenching”. The 2D conjugation nature of P2 provided multi migration channel for excitons , which resulted in the remarkably enhanced super-quenching.
研究领域:
材料科学
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化学
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Yi Zhou,Wenfeng Zhao
Designing a low-cost and efficient photocatalytic system to produce high-valuable carbonates from the cycloaddition of CO 2 by using clean and renewable sunlight as the driving force shows great research potential. Here, a commercially available 4,4''-diamino-p-terphenyl (DT) was directly employed to promote the photocatalytic cycloaddition of CO 2 and various epoxides under visible light irradiation. As high as 95 % yield of target carbonate was obtained using blue LED (>450 nm) as a light source for 6 h under solvent-free/atmospheric CO 2 /room temperature conditions. Even under irradiation of natural light, a good yield of 68 % carbonate can also be achieved under ambient conditions. Moreover, in situ EPR and a series of controlled experiments were conducted to investigate the plausible photocatalytic mechanism, demonstrating that amino-containing DT with both π-π and p-π conjugated structure provides abundant basic sites and photogenerated electrons/holes as active sites for CO 2 activation and ring opening of epoxides at the same time.
研究领域:
化学
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环境科学
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材料科学
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DOI
高影响因子
SYNTHETIC METALS
·
2021
·
IF 3.266
Yueqiang Ma,Yuchang Du,Chunxia Li,Yan Zhang,Hongmei Du,Jinsheng Zhao,Junhong Zhang,Yu Xie
In this work, starting from cyclopenta[2,1-b;3,4-b′]dithiophene (CPDT) and tris(thienothiophene) (3TT) as donor units, and diketopyrrolopyrrole (DPP) as the acceptor unit, three new solution-processable donor-acceptor conjugated copolymers (P1, P2, P3) were successfully synthesized through the palladium-catalyzed Stille coupling reaction. The monomer molar feeding ratios (CPDT:DPP:3TT) of the three polymers are 3:2:1, 2:1:1, 3:1:2, respectively, which are named as PCPT-1, PCPT-2, and PCPT-3. For comparison purpose, we also synthesized the binary copolymers between CPDT and DPP (PCP), CPDT and 3TT (PCT), and compared their properties with the ternary copolymers. The optical band gaps of the five polymers were all lower than 1.9 eV, and they all showed abundant color changes. During the oxidation process , PCPT-1 changed from purple to cyan-gray and turned to earthy brown finally, PCPT-2 changed from purple in a neutral state to blue-gray in an oxidized state. Similarly, PCPT-3 turned from purple to cement gray and finally oxidized to light blue. PCP polymer changed from dark green in a neutral state to cement gray in an oxidized state, PCT polymer changed from purple in a neutral state to Light gray purple in an oxidized state. The electrochromic kinetic performance study showed that the response time of the five polymers was about 1 s within a 4-second interval. In the dynamic stability test of 750 cycles (6000 s), the five polymers demonstrated good stability. The contrast retention of polymer PCPT-2 at 570 nm reached to as high as 96.17%.
研究领域:
材料科学
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化学
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DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2021
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IF 3.493
Yue Shan,Weili Yu,Lijuan Shen,Xuan Guo,He Zheng,Jinyi Zhong,Tao Hu,Yinglun Han
Haloalkane dehalogenase DhaA catalyzes the hydrolytic cleavage of carbon-halogen bonds and produces alcohol, a proton and a halide. However, DhaA suffers from the poor environmental stability, such as sensitivity to high temperature, low pH, hypersaline and organic solvent. In order to improve the environmental stability of DhaA, DhaA was covalently conjugated with inulin, a hydrophilic polysaccharide in the present study. Each DhaA was averagely conjugated with 7∼8 inulin molecules. The conjugated inulin could form a hydration layer around DhaA, which increased the conformational rigidity and decreased the entropy of the enzyme. Conjugation of inulin maintained 75.5 % of the enzymatic activity of DhaA and slightly altered the structure of DhaA. As compared with DhaA, the conjugate (inu-DhaA) showed slightly different kinetic parameters (K m of 2.9 μmol/L and K cat of 1.0 s −1 ). Inulin conjugation could delay the structural unfolding and/or slow the protonation process of DhaA under undesirable environment, including the long-term storage, low pH, hypersaline and organic solvent stability. As a result, the environmental stability of DhaA was markedly increased upon conjugation with inulin. Thus, inulin conjugation was an effective approach to enhance the environmental stability of DhaA.
研究领域:
生物化学
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酶工程
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DOI
PubMed
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2021
·Vol. 330
·期 3
·1165-1176
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IF 1.371
Xu Yuwei,Tian Yin,Chen Bo,Yan Zijun,Ding Jie,Huang Yalin,Kang Jinyang,Chen Shanyong,Jin Yongdong,Xia Chuanqin
In this paper, porphyrin-based cationic conjugated network (PCCN) nanosheets were synthesized, and its adsorption for TcO 4 − /ReO 4 − was investigated. This material was stacked with AB dislocation, with an aperture of 1.2 nm. The Re(VII)/Tc(VII) adsorption kinetics of PCCN is extremely fast, and the adsorption capacity is relatively large, the selective order is ReO 4 − > NO 3 − > Cl − . XPS and DFT revealed that the exchange of Cl − on PCCN with ReO 4 − , while the hydrophobic pore of PCCN are the keys to improve adsorption selectivity. It could be used to remove Tc from groundwater around nuclear facilities. Graphic abstract
研究领域:
材料科学
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环境科学
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放射化学
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DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
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2021
·Vol. 222
·期 10
·2000418
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IF 2.527
Haoting Zheng,Kun Wu,Weilong Chen,Bingfei Nan,Zhencai Qu,Mangeng Lu
A series of copolymers of poly3-alkylthiophene (PTm) with different side chain lengths and copolymers of 3-butylthiophene and 3-butoxythiophene (PTDx) with different ratios are synthesized by oxidative polymerization. As the length of the side chain decreases, WAXD patterns of PTm show an increase in crystallinity. An increment of 50% in thermal conductivity is observed and the maximum thermal conductivity reaches to 0.320 Wm –1 K –1 . For PTDx, as the proportion of 3-butoxythiophene increases, the UV spectrum appears red-shifted, indicating an enhanced degree of p-π conjugation. The thermal conductivity of PTDx is increased from 0.340 to 0.374 Wm –1 K –1 , which is around twice that of traditional thermoplastics. Molecular dynamics (MD) is used to simulate the changes in the volume and dihedral angle overlap of the polymer at different temperatures, and achieves the same result as the experiment. MD simulations and experimental measurements have shown that reducing steric hindrance and enhancing p-π conjugation can increase the thermal conductivity of the polymer. Young's modulus of PTDx (around 1.86 GPa) is lower than that of conventional plastics, and its flexibility makes it more versatile.
研究领域:
材料科学
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物理学
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DOI
高影响因子
Forests
·
2023
·Vol. 14
·期 6
·1094
·
IF 2.9
Renjie Li,Junyuan Li,Jiangtao Shi,Yongyue Zhang,Yuxin Sun,Yuxi Chen,Zhipeng Liu
The water immersion ofPterocarpuswood produces strong blue fluorescence, which comes from the extract. The fluorescence contained in the extract is of interest for the identification ofPterocarpuswood. We conducted an investigation into the extraction solution ofPterocarpuswood and analyzed the mechanism of fluorescence in this species. Possible species of the fluorescent molecules are discussed based on the mixture. Liquid chromatography mass spectrometry (LC-MS) is used for an analysis of the extract, the obtained substances that may be fluorescent inPterocarpuswood. In addition, the change in the fluorescence intensity with changes in the pH and concentration in the extract is also studied. The results show that the fluorescent molecule is quenched by aggregation (Aggregation-Caused Quenching; ACQ) and is unstable in over-acidic and over-alkaline conditions (especially acidic).Keywords:Pterocarpuswood;extract solution;fluorescence intensity;conjugate structure
研究领域:
植物学
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化学
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DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
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2022
·
IF 9.336
Sairui Zhang,Xueqi Li,Xiaojia Yan,David Julian McClements,Cuicui Ma,Xuebo Liu,Fuguo Liu
The aim of this study was to prepare lactoferrin-epigallocatechin-3-gallate (LF–EGCG) conjugates and to determine their ability to protect emulsified algal oil against aggregation and oxidation. LF–EGCG conjugates were formed using an ultrasound-assisted alkaline treatment. The ultrasonic treatment significantly improved the grafting efficiency of LF and EGCG and shortened the reaction time from 24 h to 40 min. Fourier transform infrared spectroscopy and circular dichroism spectroscopy analyses showed that the covalent/non-covalent complexes could be formed between LF and EGCG, with the C O and C N groups playing an important role. The formation of the conjugates reduced the α-helix content and increased the random coil content of the LF. Moreover, the antioxidant activity of LF was significantly enhanced after conjugation with EGCG. LF–EGCG conjugates as emulsifiers were better at inhibiting oil droplet aggregation and oxidation than LF alone. This study demonstrates that ultrasound-assisted formation of protein–polyphenol conjugates can enhance the functional properties of the proteins, thereby extending their application as functional ingredients in nutritionally fortified foods.
研究领域:
食品科学
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化学工程
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生物技术
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营养学
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产品关联
DOI
PubMed
高影响因子
Methods and Applications in Fluorescence
·
2022
·Vol. 11
·期 1
·015001
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IF 3.849
Lindan Gong,Lixiao Zhang,Rui Shen,Lin Zhang,Hengyuan Wang,Lu-an Fan
A novel ionic conjugated polymer fluorescent probe (IP) containing fluorenyls and imines was synthesized through a simple condensation method for the rapid detection of Cu2+. The probe exhibited a selective quenching response toward Cu2+ over other common metal ions in phosphate-buffered saline (PBS) at a pH of 7. Moreover, the fluorescence intensity of IP was linearly proportional to the concentration of Cu2+ when it ranged from 1 to 10 μM, and the limit of detection for Cu2+ was 0.45 μM. Furthermore, the quenched fluorescence of IP by Cu2+ was recovered after adding amino acids or ethylenediaminetetraacetic acid (EDTA), indicating that the probe could be recycled and is promising to reduce the detection cost of Cu2+ in real samples.
研究领域:
分析化学
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材料科学
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DOI
高影响因子
Journal of Food Measurement and Characterization
·
2024
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IF 2.9
Liu Jianying,Ma Yan,Ukwatta Ruchika Hansanie,Xue Feng,Xiong Xiaohui,Li Chen
The conjugates of gluten and polyphenols (naringin, hesperetin or curcumin) were produced by alkaline method and the effects of conjugation on physicochemical properties of gluten were investigated in this study. The results show that the conjugates possess lower content of free amino and sulfhydryl groups, and higher molecular mass, which indicate the covalent binding occurred. As compared with corresponding mixtures, the conjugates show lower intensity of the amide A, surface hydrophobicity, intermolecular β-sheets, interfacial and surface tension, as well as higher fluorescence intensity, antiparallel β-sheets and particle size (in the range of 130–150 μm). Furthermore, the conjugates also exhibit better emulsifying and foaming properties, higher storage modulus and lower degradation temperature than native gluten. However, the changes in physicochemical properties of conjugates depend on the type of polyphenols and curcumin-gluten conjugates possess the improved emulsifying, foaming and gelation properties among conjugates, due to their more flexible structure.
研究领域:
食品科学
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生物化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2017
·
IF 3.671
Xiuting Hu,Yu Wang,Chengmei Liu,Zhengyu Jin,Yaoqi Tian
Uricase was conjugated with dextrin to improve its stability. Firstly, dextrin was succinylated into dextrin monosuccinate with the functional group, carboxylic acid, and dextrin monosuccinates with different degree of substitution (DS) were prepared. Secondly, dextrin-uricase conjugate was synthesized by uricase and dextrin monosuccinate, which was verified by size-exclusion chromatography and anion exchange chromatography . Thirdly, it was found that the conjugate degree of the dextrin-uricase conjugate was positively related to the DS of dextrin monosuccinate, but the activity was seriously lost and difficult to recover by α-amylase. When the molar ratio of dextrin monosuccinate (DS = 0.283) to uricase was 30:1, the conjugate degree of dextrin-uricase conjugate reached 22.1% and the activity was decreased to 40.4%. After triggered by α-amylase, the activity was recovered to 83.4%. Finally, the enzymatic properties of this dextrin-uricase conjugate were investigated and compared with those of free uricase. The optimal pH and temperature of the dextrin-uricase conjugate was 9.0 and 45 °C, respectively, whereas the optimal pH and temperature of free uricase was 8.5 and 45 °C, respectively. Furthermore, dextrin-uricase conjugate was more resistant to simulated physiological conditions and trypsin. These results suggested that the stability of uricase could be ameliorated by conjugation with dextrin.
研究领域:
生物化学
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医学
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产品关联
DOI
PubMed
高影响因子
DYES AND PIGMENTS
·
2021
·
IF 4.889
Peng Wu,Yuan Xiong,Chen Lei,Yuan Li,Xiang Liu,Cheng Zhang,Yudie Sun,Jian Zhang,Chun-Sing Lee,Kui Zhang
Carbon dots or Carbon quantum dots (herein after abbreviated as CDs) with bight luminescence, derived from carbohydrates such as citric acid , glucose or sucrose, have been widely reported in recent publications. However, as to which functional groups and structures in CDs are responsible for luminescence, most explanations in current references are normally based on assumptions, instead of being convinced by the accurate information resting on experimental facts. Herein, we conducted an experimental study targeting at finding the fluorophores of CDs prepared from citric acid and glycine by fluorescent quenching. The experimental results revealed that the essence of fluorescence was manipulated by fluorophores of conjugated C C double bonds and aldehyde groups. The destruction of aldehyde groups or C C double bonds in the CDs led to a complete decay of luminescence. In addition, the results of this experiment were similar to those of CDs prepared from the sole citric acid, glucose or sucrose, which predicted the analogy of the CDs in chemical structures . Such information about fluorophore of CDs was valuable for further exploring more extensive application of CDs in sense technologies.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）