LANGMUIR
·
2020
·
IF 3.557
Ting Zhao,Ruifeng Qian,Yang Tang,Jing Yang,Yitao Dai,Wan In Lee,Jia Hong Pan
Although considerable progress has been achieved in the preparation of uniform hydrous TiO2 spheres (HTS) through the sol–gel process, there is plenty of room left in tailoring the size and morphology of HTS on the deep-submicron scale or even nanoscale since the diameters of the so far reported HTS are mostly on the (sub)micron scale (0.3–1.2 μm). Here, we develop a novel titanium tetraisopropoxide (TTIP)–organic acid (OA)–acetonitrile (ACN)–methanol (MeOH)–H2O system, which facilitates the control of nanoporous HTS to the range of 50–300 nm. The synthetic parameters including OA, (co-)solvent, concentration of precursor, and reaction temperature are comprehensively optimized, aiming at reproducible preparation and precise size control. Among the various OAs, n-valeric acid presents the best capability in controlling the spherical morphology and size uniformity. The synthesized amorphous HTS containing numerous micropores and mesopores show excellent hydrothermal stability and offer suitable self-template for the subsequent synthesis of mesoporous anatase TiO2 spheres (MAT) with a large surface area of 99.1 m2/g. The obtained TiO2 deep-submicrospheres and nanospheres with tunable sizes show great potential in various research fields.
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TALANTA
·
2019
·
IF 4.916
Shengrui Xu,Qingqing Liu,Cuicui Wang,Li Xiao,Suling Feng,Ning Li,Chang-Po Chen
In this study, facile fabrication of three-dimensional (3D) pompon-like gold/zinc oxide (Au/ZnO) porous microspheres by hydrothermal procedure was investigated. These microspheres were utilized as solid phase microextraction (SPME) coating for determination of volatile fatty acids (VFAs) from foot odor coupling with gas chromatography-mass spectrometry (GC-MS). SEM and TEM characterizations showed that as-prepared material was composed of 1D porous nanowires and presented a uniform coating on stainless-steel wire. The extraction of VFAs including propanoic acid, butyric acid , isobutanoic acid, isovaleric acid , hexanoic acid , and heptylic acid was carried out by headspace model after sampling from human foot using cotton wool strips. Following optimization of extraction parameters including extraction temperature and time and desorption temperature and time, the as-prepared SPME coating presented better extraction efficiency than commercial DVB/CAR/PDMS fiber towards all the VFAs due to its excellent properties. Under the optimized conditions, the method exhibited good linearity (0.5–200 ng) with regression coefficients (R 2 ) ranging from 0.9836 to 0.9981 for all the analytes. The limits of detection ranged from 0.017 to 0.098 ng. Single fiber repeatability varied from 6.5% to 11.2% and the fiber-to-fiber reproducibility ranged from 8.6% to 12.3%. The proposed method was successfully applied for extraction and determination of VFAs from foot odor after sampling using cotton wool strips.
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ACS Applied Nano Materials
·
2019
·
IF 0
Qin Dai,He Zhao,Hongbin Cao,Yiqiu Wu,Zhi Sun,Xiaofei Meng,Tianyu Wang,Guangfei Yu,Jingyi Lin,Rong Hou
The green and low-cost preparation of carbon dots (CDs) with excellent fluorescence plays a key role in cell-imaging applications. Herein, we develop a green photochemical approach for fabricating CDs. The produced CDs can be used directly in lung cancer A549 cell imaging without any tedious post-treatments. As nontoxic and green alternatives to prevent pollution, fatty acids in sole aqueous media are the only reactants used to synthesize CDs. Furthermore, the green process of photoirradiation avoids harsh conditions, such as strong acids and bases, strong oxidants, and high temperatures and pressures. In addition, the by-products remaining in the aqueous environment are fatty acid dimers in the form of vesicles, which can also be recycled as gemini surfactant resources. We demonstrate that this green synthetic method for fabricating CDs is suitable for fatty acids with different chain lengths, and therefore, exhibits considerable universality. Fatty acids, as readily available green resources in nature, and the green and simple synthesis method without additional pollution provides a new approach and perspective for the green synthesis of CDs for bioimaging.
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ADVANCED POWDER TECHNOLOGY
·
2018
·
IF 2.943
Junkai Cao,Xue-Zhi Song,Xiaolan Kang,Zideng Dai,Zhenquan Tan
Herein, we report a facile one-pot solvothermal method to prepare unique oleic acid (OA) modified monodispersed mesoporous TiO 2 nanospheres with carboxylate ligands from the oleic acid in the bidentate chelating linkage mode. The mesoporous OA-TiO 2 nanospheres have a very large specific surface of nearly 510 m 2 /g. The oleic acid cannot only act as a binding ligand to control the shape of mesoporous TiO 2 nanospheres, but also be benefit to enhance the visible-light absorption. The mesoporous OA-TiO 2 nanospheres exhibit an excellent photocatalytic performance in the degradation of Rhodamine B and phenol under the visible light irradiation and show almost no attenuation after four cycles.
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Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 46
·7750-7759
·
IF 4.776
Zhaoming Guo,Kun Zheng,Zhenquan Tan,Ye Liu,Ziyin Zhao,Guang Zhu,Kun Ma,Changhao Cui,Li Wang,Tianyu Kang
The resistance of tumor cells is a major cause of chemotherapy failure in cancer patients. Photodynamic therapy (PDT) as a noninvasive treatment strategy with high specificity is a promising method for the treatment of cancer. In this study, a CD44 and N-cadherin dual targeting drug delivery system in combination with mesoporous titanium dioxide nanoparticle (MTN)-based PDT has been successfully constructed for overcoming drug resistance. Hyaluronic acid (HA) and ADH-1 (a cyclic pentapeptide) were grafted onto the surface of MTN to construct ADH-1-HA-MTN, and doxorubicin (DOX) was selected as a model drug. HA can both trap DOX in the wells of MTN and target CD44-overexpressing tumor cells. ADH-1 blocks the EMT process of tumor cells by selectively inhibiting the function of N-cadherin. Besides, a large number of reactive oxygen species (ROS) were generated by MTN under X-ray irradiation, which could provide a cancer cell killing effect. Cytotoxicity tests showed that ADH-1-HA-MTN/DOX was more toxic to tumor cells than its non-ADH-1 modified counterparts. Western blotting analysis showed that ADH-1-HA-MTN/DOX overcame the drug resistance of tumor cells by preventing the process of epithelial–mesenchymal transition. Taken together, ADH-1-HA-MTN may be a promising targeted drug delivery system to overcome the drug resistance of tumors.
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JOURNAL OF MEDICAL ENTOMOLOGY
·
2018
·Vol. 55
·期 4
·787-794
·
IF 1.968
Tian Jiaxin,Mao Jie,Yu Baoting,Fouad Hatem,Ga’al Hassan,Mao Guofeng,Mo Jianchu
Efforts to develop mosquito attractants using vertebrate host volatiles have been well made under laboratory conditions but their attractiveness to mosquitoes in the wild still needs to be evaluated. In the present study, we evaluated the attraction of female Culex pipiens pallens Coquillett (Diptera: Culicidae) to 11 individual chemical compounds found in vertebrate host odors, and to synthetic blends, consisting of different combinations of the compounds. These tests were conducted under laboratory and field conditions using a Y-tube olfactometer and odor-baited traps, respectively. When delivered at concentrations ranging from 0.1 to 10.0 μg/kg, 9 of the 11 compounds were attractive to female mosquitoes under laboratory conditions. We developed 47 synthetic blends composed of the 6 most attractive compounds (propionic acid, hexanal, myristic acid, benzaldehyde, 1-octen-3-ol, and geranyl acetone) and 18 of them were significantly attractive to mosquitoes in the olfactometer. Most of the attractive blends contained two to four attractive compounds. In the field, 5 of the 18 blends captured significantly more mosquitoes than did control traps. The findings demonstrate that female mosquitoes can be attracted by single chemical compounds as well as some of their synthetic blends. The effectiveness of synthetic blends depended on specific combinations of several compounds, rather than simply increasing the number of attractive compounds in the blends. Synthetic blends may have potential for use in odor-baited traps for mosquito surveillance.
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CATALYSIS COMMUNICATIONS
·
2013
·
IF 2.915
Hong-De Yan,Qun Zhang,Zhao Wang
A lipase from Aspergillus oryzae WZ007 exhibited high esterification activities toward a series of short-chain acids and alcohols. Moreover, it displayed a strong tolerance for high substrate concentration of up to 2.0 M and presented a highest initial rate of 276 mmol·L − 1 ·h − 1 at this concentration. After a reaction time of 48 h, the conversion rates of acids were higher than 80% for the synthesis of a majority of heptanoic acid esters, some octanoic acid esters and n -propyl hexanoate. These results implied that A. oryzae WZ007 lipase was a promising biocatalyst in the production of flavor esters.
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Scientific Reports
·
2015
·Vol. 5
·期 1
·1-6
·
IF 5.578
Yao Feng,Yi Bin,Shen Caihong,Tao Fei,Liu Yumin,Lin Zhixin,Xu Ping
Luzhoulaojiao liquor is a type of Chinese liquor that dates back hundreds of years, but whose precise chemical composition remains unknown. This paper describes the screening of the liquor and the identification of its compounds using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOF-MS). Samples were prepared by both liquid-liquid extraction and solid-phase microextraction, which facilitated the detection of thousands of compounds in the liquor, thus demonstrating the superior performance of the proposed method over those reported in previous studies. A total of 320 compounds were common to all 18 types of Luzhoulaojiao liquor studied here and 13 abundant and potentially bioactive compounds were further quantified. The results indicated that the high-performance method presented here is well suited for the detection and identification of compounds in liquors. This study also contributes to enriching our knowledge of the contents of Chinese liquors.
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Analytical Methods
·
2013
·Vol. 5
·期 19
·5037-5043
·
IF 1.855
Yingtang Li,Yang Jiao,Yuhong Guo,Yaling Yang
A new and fast microextraction technique termed vortex-assisted supramolecular solvent microextraction (VASUSME) has been developed. The method was based on the microextraction of endocrine disrupting compounds (EDCs), including bisphenol-A (BPA), 2,4-dichlorophenol (2,4-DCP), bisphenol-AF (BPAF) and tetrabromobisphenol-A (TBBPA) in 10 mL sample with 500 μL of a supramolecular solvent (SUPRASs), and then detection by high-performance liquid chromatography (HPLC). In the VASUSME procedure, dispersion of microvolumes of a low density extraction solvent into the aqueous sample is achieved by vortex mixing, a mild emulsification procedure. Under the optimum conditions, the repeatability of the proposed method was found to be good. The relative standard deviations (RSD, n = 5) were 3.98–5.64%. The limits of detection (LOD) were in the range of 0.14–0.32 ng mL−1 and the limits of quantification (LOQ) were in the range of 0.41–1.02 ng mL−1. All correlation coefficients of the calibration curves were higher than 0.998. Recoveries of the EDCs spiked into samples of liquid foods and their packaging materials were in the range of 91% to 105.1%. The VASSUSME method was successfully applied to the analysis of BPA, 2,4-DCP, BPAF and TBBPA in samples of liquid foods and their packaging materials. Moreover, the method is simple, sensitive and environmentally-friendly and consumes much less solvent than traditional methods.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2014
·Vol. 95
·期 5
·915-921
·
IF 1.879
Liang Dong,Yingmin Hou,Feng Li,Yongzhe Piao,Xiao Zhang,Xiaoyu Zhang,Cheng Li,Changxin Zhao
BACKGROUND Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. RESULTS Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. CONCLUSION Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 30
·7063-7075
·
IF 3.431
Wang Meng,Jiao Yang,Cheng Chunsheng,Hua Jianhao,Yang Yaling
A novel and sensitive method based on nitrogen-doped carbon quantum dots as a fluorescence probe coupled with magnetic solid-phase extraction (MSPE) purification for analysis of folic acid (FA) in human serum samples has been established for the first time. In the developed system, magnetic nanoparticles coated with hexanoic acid (Fe 3 O 4 @C 6 ) were synthesized by a one-step chemical co-precipitation method with good magnetic properties and dispersibility for sample purification, and it is better to be separated from the sample. High fluorescence nitrogen-doped carbon quantum dots (N-CQDs), simply prepared using a one-step hydrothermal method with nitrilotriacetic acid, could be selectively quenched by FA. Based on this phenomenon, a fluorescence assay was proposed for specific determination of FA. Various operational experiment parameters have been studied and optimized in detail. Under the optimum experimental conditions, the detection limit of the proposed method for FA was evaluated to be 0.5 nM (S/ N = 3), while the relative standard deviation (RSD) was 1.2% ( n = 6). Finally, the proposed method was applied for determination of trace levels of FA from human serum samples and quantitative recoveries were achieved within the range of 95.7–103.5%. All of the results showed that the proposed method had significant application in further research.
Schematic of synthesis of N-CQDs and schematic of suggested mode for analysis of folic acid (FA).
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JOURNAL OF CHROMATOGRAPHY A
·
2024
·
IF 3.8
Yanhui Zhang,Hongbo Li,Xiaoqin Hai,Xiaoli Guo,Xin Di
A green and recyclable switchable supramolecular deep eutectic solvent (SS-DES) was designed and prepared for effective extraction of flavonoids from Scutellariae Radix . The novel SS-DES has both excellent extraction performance of DES and the host guest inclusion of cyclodextrin, thereby showing superior extraction efficiency and selectivity. The characteristic of polarity switching can endow the SS-DES with achieving homogeneous extraction and rapid two-phase separation, shorting per-treatment time largely. Parameters affecting the extraction performance were investigated by the response surface methodology. The results indicated that the SS-DES showed better extraction yield of total flavonoids (157.95 mg/g) compared with pure DES (135 mg/g) and traditional organic solvent (60 % ethanol, 104.87 mg/g). Moreover, the switching mechanism of SS-DES was characterized by FT-IR and 1 H NMR, and the extraction mechanism was studied by density functional theory and molecular docking analysis. After evaluating the ecological impact of the method, the cytotoxicity of SS-DES was investigated and the result displayed that its toxicity was very low or even negligible with the EC 50 >2000 mg/L. After being adsorbed by macroporous AB-8 resin, the regenerated SS-DES was recycled 5 times and the extraction efficiency still remained above 90 %, indicating the desirable reusability. Therefore, the proposed method was efficient and sustainable, and revealed favorable application prospect for the extraction of bio-active compounds from plant materials.
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