RSC Advances
·
2020
·Vol. 10
·期 56
·33635-33641
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IF 3.119
Meihua Lin,Xin Ma,Shijun Lin,Xiaojin Zhang,Yu Dai,Fan Xia
Carbon dots (CDs) as fluorescent probes have been widely exploited to detect biomarkers, however, tedious surface modification of CDs is generally required to achieve a relatively good detection ability. Here, we synthesized N-doped carbon dots (N-CDs) from triethylenetetramine (TETA) and m-phenylenediamine (m-PD) using a one-step hydrothermal method. When the pH increases from 3 to 11, the fluorescence intensity of the N-CDs gradually decreases. Furthermore, it displays a linear response to the physiological pH range of 5–8. Au3+ is reduced by amino groups on the surface of N-CDs to generate gold nanoparticles (AuNPs), causing fluorescence quenching of the N-CDs. If glutathione (GSH) is then added, the fluorescence of the N-CDs is recovered. The fluorescence intensity of the N-CDs is linearly correlated with the GSH concentration in the range of 50–400 μM with a limit of detection (LOD) of 7.83 μM. The fluorescence probe was used to distinguish cancer cells from normal cells using pH and to evaluate intracellular GSH. This work expands the application of CDs in multicomponent detection and provides a facile fluorescent probe for the detection of intracellular pH and GSH.
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高影响因子
ANALYTICAL CHEMISTRY
·
2020
·
IF 6.785
Xue Zhao,Gang Wu,Wenpeng Zhang,Mengqiu Dong,Yu Xia
Sphingomyelins (SMs) are an essential class of lipids widely existing in different organisms. The sphingoid base and N-acyl chain are two building blocks which can undergo different types of modifications during lipogenesis, including desaturation, hydroxylation, and methyl branching. Current lipidomic analysis methods cannot provide detailed information on these structural motifs. Herein, we developed a tandem mass spectrometric method by harnessing radical-directed dissociation (RDD) from collision-induced dissociation (CID) of the bicarbonate anion adduct of SM ([M + HCO3]−). A major RDD channel produced a high-abundance fragment carrying the intact N-acyl chain, termed as “N-acyl fragment”, allowing the assignment of the sphingoid base/N-acyl composition and relative quantitation of compositional isomers of SM at high sensitivity. RDD also produced intrachain fragments in lower abundances, which helped localization of methyl branching and hydroxylation in SM. The acetone Paternò–Büchi (PB) reaction was found to be capable of derivatizing the Δ4 carbon–carbon double bond (C═C) in sphingosine (SPH) base and producing C═C diagnostic ions upon CID, albeit at much lower efficiencies than those of the isolated C═C in alkyl chains. A liquid chromatography–mass spectrometry workflow was developed by incorporating MS2 CID of SM via [M + HCO3]− and PB-MS2 CID. The capability of profiling SM with detailed structural information was demonstrated by analyzing complex lipid extracts from porcine brain and Caenorhabditis elegans. These results provided visualization of the sphingoid base/N-acyl compositional isomers of SM lipids and revealed large structural diversity from each sample. These included identification of the sphingadiene base [d18:1(Δ4,14)], C═C location isomers in N-acyls, C-2 hydroxylation of N-acyls, and iso-methyl branched SPH base.
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JOURNAL OF FOOD SCIENCE
·
2021
·Vol. 86
·期 2
·546-562
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IF 3.167
Yadi Liu,Guoxiao Lai,Yinrui Guo,Xiaocui Tang,Ou Shuai,Yizhen Xie,Qingping Wu,Diling Chen,Xujiang Yuan
Previous research has shown that the extracts from the Ganoderma lucidum spore (GS) have potentially cardioprotective effects, but there is still abundant room for development in determining its mechanism. In this study, the rat model of cardiac dysfunction was established by intraperitoneal injection of trimethylamine- N -oxide (TMAO), and the extracts of GS (oil, lipophilic components, and polysaccharides) were given intragastrically at a dose of 50 mg/kg/day to screen the pharmacological active components of GS. After 50 days of treatments, we found that the extraction from GS reduced the levels of total cholesterol, triglyceride, and low-density lipoprotein; increased the levels of high-density lipoprotein; and reduced the levels of serum TMAO when compared to the model group ( P < 0.05); especially the GS polysaccharides (DT) and GS lipophilic components (XF) exhibited decreases in serum TMAO compared to TMAO-induced control. The results of 16S rRNA sequencing showed that GS could change the gut microbiota, increasing the abundance of Firmicutes and Proteobacteria in the DT-treated group and XF-treated group, while reducing the abundance of Actinobacteria and Tenericutes . Quantitative proteomics analysis showed that GS extracts (DT and XF) could regulate the expression of some related proteins, such as Ucp1 (XF-TMAO/M-TMAO ratio is 2.76), Mpz (8.52), Fasn (2.39), Nefl (1.85), Mtnd5 (0.83), Mtnd2 (0.36), S100a8 (0.69), S100a9 (0.70), and Bdh1 (0.72). The results showed that XF can maintain the metabolic balance and function of the heart by regulating the expression of some proteins related to cardiovascular disease, and DT can reduce the risk of cardiovascular diseases by targeting gut microbiota.
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CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yihao Liu,Riyue Ge,Yingying Chen,Mengqiu Huang,Ruijie Zhu,Wenxian Li,Yi Liu,Lingyan Feng,Renchao Che
The electrocatalytic water splitting into oxygen (O 2 ) and hydrogen (H 2 ) is one of promising technique for addressing the problem of energy shortage. Owing to the sluggish reaction kinetics for oxygen evolution reaction (OER), it is urgent to explore efficient and inexpensive OER electrocatalytic materials. Herein, a highly efficient three-dimensional (3D) hybrid of anions (Cl − and CO 3 2− ) doped cobalt hydroxide catalyst coupled with nitrogen-doped carbon dots (Co(OH) 2 @NCDs) is reported via a simple in situ hydrothermal method. Interestingly, the additional mass ratio of NCDs in Co(OH) 2 hybrid has strong influence on the morphology of as-prepared composites. The well-defined urchin-like Co(OH) 2 @NCDs composite exhibits superior OER performance, achieving the low overpotential ( η ) of 296 mV at 10 mA cm −2 and high durability in 1 M KOH solution. The urchin-like Co(OH) 2 @NCDs catalyst could achieve 29-fold electrochemical active surface area than that of the pure Co(OH) 2 . Additionally, after coupling with NCDs, analysis result shows new Co-N charge transfer channel is generated in hybrid and an optimized electronic environment is originated from the strong electronic interaction among Co atom and NCDs, which can provide efficient charge channels for the rapid electron transfer and further improve the intrinsic activity and promote the OER kinetics. The work may endow a new strategy for the construction of excellent transition metal-based hydroxide water oxidation electrocatalysts.
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Catalysts
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2020
·Vol. 10
·期 10
·1126
·
IF 3.52
Jun Liu,Xuli Li,Haobo Hou,Min Zhou
To further boost the charge separation and photocatalytic activity of TiO2under visible light, the anatase–rutile mixed-phase nitrogen-doped (N-doped) TiO2nanoparticles were successfully synthesized through a facile one-step calcining procedure using TiN as raw materials. The crystal phases, morphologies, chemical compositions, textural structures, and optical properties of as-obtained N-doped TiO2were characterized by the corresponding analytical techniques. The photocatalytic activities of as-fabricated samples were evaluated by degrading 4-chlorophenol (4-CP) and methylene blue (MB) aqueous solution under visible light irradiation. The results revealed that the ratio of rutile to anatase increased with the improvement of sintering temperature, and the sample prepared at 500 °C had the best photocatalytic activity. This might be because it possessed the most appropriate rutile/anatase proportion as well as the nitrogen doping. The transient photocurrent responses, photoluminescence spectra (PL) measurements, and active species trapping experiments were implemented to disclose the photocatalytic mechanism. This work will provide a further insight into the synthesis of highly efficient N-doped TiO2photocatalysts for organic contaminant removal.Keywords:N-doped TiO2;charge separation;photocatalytic activity
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JOURNAL OF CHEMICAL RESEARCH
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2020
·
IF 0.593
Xiaolin Hu,Lei Liu,Yue Zhang,Aibing Chen
Carbon-based materials with multidimensional structures generally exhibit improved properties compared with single-morphology carbon materials for various applications including catalysis, adsorption, and energy storage. Here, an N-doped mesoporous carbon sphere and sheet composite is prepared by a co-assembly strategy using an ionic liquid ([C18Mim]Br) as the structure-directing agent, ethylenediamine as the catalyst, tetraethyl orthosilicate as the pore-forming agent, and resorcinol formaldehyde resin as the carbon precursor. [C18Mim]Br and ethylenediamine not only induce formation of the unique structure but also lead to in situ nitrogen doping on the N-doped mesoporous carbon skeleton. The obtained N-doped mesoporous carbon shows a unique composite structure of thin sheets embedded with carbon spheres, having high a specific surface area and uniform mesopore distribution. When used as an electrode material, the N-doped mesoporous carbon shows a good specific capacity of 273 F g−1 at a current density of 0.5 A g−1 and a good rate capability (82.1% of the capacitance is retained at a high current density of 10 A g−1). Moreover, the N-doped mesoporous carbon exhibited ideal stability behavior (91.6% capacitive retention after 10,000 cycles), indicating a promising role as an electrode material for excellent performance supercapacitors.
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ENVIRONMENTAL RESEARCH
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2020
·
IF 5.715
Zexiang Wang,Lihui Huang,Yuxia Wang,Xiaoming Chen,Hongfei Ren
Metal-free catalysts are widely considered as promising alternatives to traditional metal-based catalysts, which can effectively activate peroxymonosulfate (PMS). In this study, a novel metal-free catalyst, carbonized polypyrrole (CPPy) was synthesized through high-temperature carbonization of PPy, easily achieving the in situ N doping without the addition of nitrogen sources. Tetracycline (TC) was selected as the target contaminant to assess the catalytic activity of the CPPy/PMS system. Enhanced catalytic activity was observed in CPPy/PMS over a wide pH range (3.0–9.0), and the removal rate of TC by CPPy-3/PMS reached 91.3% after 10 min. After regenerating the used catalyst, the catalytic activity was refreshed, implying its stability and recyclability . The catalytic degradation of TC by CPPy/PMS was mainly attributed to a non-radical process. CPPy, as an intermediary, grabbed electrons from the electron-donating groups of TC and transferred them to the PMS molecule. Thereafter, TC that lost electrons was oxidized and degraded, and the O–O bonds of PMS were destroyed by the transferred electrons to form S O 4 2 − and OH − . Moreover, O ⋅ 2 − and 1 O 2 were involved in TC degradation . TC degradation pathway was investigated through HPLC-MS analysis. These findings provide a promising strategy for the construction of catalysts for PMS and environmental remediation.
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JOURNAL OF ELECTROANALYTICAL CHEMISTRY
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2020
·
IF 3.807
Yuan Li,Yuyang Wei,Wenbin Zhang
The effect of proton acceptor on the electrochemistry of proton-coupled electron transfer reagents is always worthy of attention. Formal potentials of NHPI with different proton acceptors have been measured by cyclic voltammetry and were used to discriminate hydrogen bonding and deprotonation engaging in the oxidation of NHPI. With the negative shifting of formal potentials, the formation of hydrogen bonding complex was suggested when adding water into NHPI acetonitrile solution, a new wave caused by the addition of one pyridine base may be caused by a deprotonation process followed by a single electron transfer step. In addition, electrooxidation reactions of benzyl alcohol mediated by hydrogen bonding or deprotonation modified NHPI have been addressed and significant findings have been reported.
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JOURNAL OF HAZARDOUS MATERIALS
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2020
·
IF 9.038
Xiang Li,Yan Jia,Minghua Zhou,Xianfa Su,Jianhui Sun
In this study, the Fe, N co-doped biochar (Fe-N-BC) was prepared by pyrolyzing wheat straw, urea and iron salts and used to activate persulfate (peroxydisulfate, PS) for organic contaminant degradation. Iron oxide doping not only introduced magnetism into the biochar for easy separation, but also influenced its catalytic ability for PS activation. In the Fe-N-BC/PS system, almost all acid orange (AO7) was removed within 90 min with an apparent rate constant ( k obs ) of 0.114 min −1 , which was almost 37 times larger than that of pure N-BC (0.003 min −1 ). Factors influencing the removal of AO7 were investigated, including PS concentration, catalyst dosage, and initial pH. The Fe-N-BC/PS system had high removal efficiencies for various organic contaminants and showed high resistance to inorganic anions in aquatic environments. The radical quenching studies, electron paramagnetic resonance (EPR) measurements, and electrochemical analyses verified that the mechanism of AO7 degradation in the Fe-N-BC/PS system included both radical and non-radical pathways involving the generation of OH, SO 4 − , O 2 − , 1 O 2 , and electron transfer. Additionally, persistent free radicals (PFRs) on the catalysts also related to their catalytic efficiencies. These results demonstrated that the Fe-N-BC/PS system had the potential for wastewater treatment applications.
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Particuology
·
2020
·
IF 2.787
Zhou Lan,Yangcheng Lu
In this work, we used the inert substances silicone oil and n -hexane to modulate the solvent environment, and in so doing tailor the preparation of magnesium ethoxide (Mg(OEt) 2 ) particles. We found the following: (1) nonpolar n -hexane mainly modulates the polarity of the solvent to control the precipitation rate and size of the Mg(OEt) 2 seeds, thereby triggering accelerated nucleation to form small primary particles; and (2) silicone oil (relatively high polarity and viscosity) facilitates the growth and agglomeration stage, to improve inter-particle dispersion and obtain relatively uniform Mg(OEt) 2 particles. We summarized these findings in a common mechanism for preparing Mg(OEt) 2 particles with uniform morphology, small size, and high bulk density as per the synergistic effect of n -hexane and silicone oil. The ratios of silicone oil and n -hexane are flexible, and afford various regular and well-dispersed Mg(OEt) 2 particles that are 5–30 μm in size and 0.2–0.7 g/cm 3 in bulk density. The nanoparticles thus have the potential to serve in diverse applications such as catalysis.
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CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Siyu Zhong,Huaizhi Liu,Donghai Wei,Jin Hu,Hang Zhang,Hongshuai Hou,Meixia Peng,Guanhua Zhang,Huigao Duan
An effective design of carbon materials with appropriate nanoarchitecture and optimized physicochemical property is critically demanded for superb lithium/sodium storage capacities. N-rich (up to 15.7%) hollow carbon nanotubes (NCNT) with long aspect ratio are well developed via a template method by exploring polypyrrole as the high nitrogen-containing carbon precursor. Owing to the hollow structure with large cavity and long aspect ratio, the NCNT exhibits Li + /Na + storage capability with favorable volume buffer and rapid ion and electron transfer at high rate, resulting in long-term cycling and high-rate property. Meanwhile, the high N content creates abundant active sites and extrinsic defects, facilitating the improved specific capacity and rate performance. Impressively, our NCNT-600 electrode displays a favorable reversible capacity of 132 mAh g −1 after 5000 cycles at 4000 mA g −1 for SIBs and 170 mAh g −1 after 2000 cycles at the same current for LIBs. Further quantitative kinetic analysis reveals the dominated capacitive contribution of Li + /Na + storage in NCNT, which is attributed to the porous hollow nanotubes and N-rich carbon with volume strain mitigation and enhanced electronic/ionic transfer capability. Given the cost-effectiveness and material sustainability, our work will shed light on the further design of other carbon-based materials for advanced energy storage devices.
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Journal of Chemistry
·
2020
·
IF 1.79
Yuchen Ya,Xiaokang Nie,Licheng Peng,Longkai Xiang,Jialong Hu,Wenlong Dong,Huaqiang Chu
Laminar diffusion flame was used to study the effect of ethanol on n-heptane flame in terms of the morphology and microstructure of soot under atomization combustion. For the same carbon mass flux at the outlet of the burner, the ratio of ethanol doping in n-heptane was changed, and the soot was collected from the axial positions of the flame at different heights using the thermophoresis probe method. The results showed that the flame height increased significantly with the increasing ratio of ethanol doping. When the ratio of ethanol and n-heptane (CE/CN) was 1.5, the flame height increased by 10 mm compared with that of pure n-heptane flame. Besides, the temperature in the center of the flame decreased with the increasing ratio of ethanol doping, but the temperature in the low position was higher than that in the pure n-heptane flame, and the temperature in the high position was lower than that in the pure n-heptane flame. However, the flame temperature was the highest when the proportion of ethanol in the mixture was greater than that of n-heptane. The temperature at the flame center decreased with the increasing ratio of ethanol doping, while the temperature at the flame edge increased with the ratio. The primary particle size of soot (soot size hereafter) in all working conditions increased with the increase of flame height, which was in line with the general growth law of soot. Moreover, the soot size at the same height decreased with the increasing ratio of ethanol doping, and this trend was most obvious at the flame height of 20 mm and 30 mm. Compared with pure n-heptane, when CE/CN was 1.5, the soot size at 20 mm and 30 mm decreased by an average of 34.83%, indicating that ethanol could inhibit the surface growth of soot particle. Furthermore, the density of soot particles collected by a single copper net decreased significantly, indicating that ethanol could reduce the production amount of soot.
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