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1.
王文栋  李在均 《应用化学》2022,39(8):1285-1293
The histidine functionalized graphene quantum dots(His-GQDs)react with ruthenium trichloride to form a stable ruthenium complex. This complex is treated in a N2 atmosphere at 600 ℃ for 1 h to obtain a ruthenium-graphene quantum dot composite (Ru-His-GQD). The results of scanning electron microscopy (SEM)and transmission electron microscopy(TEM)analysis demonstrate that Ru-His-GOD has one three-dimensional structure. The diameter of ruthenium nanoparticles is between 40 and 60 nm. Ru-His-GQD is rich in functional groups and has high oxidase-like activity. Based on Ru-His-GQD catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine(TMB)to produce blue compounds,a photometric method for the determination of phoxim in carrots is established. Phoxim can inhibit the activity of Ru-His-GQD oxidase,resulting in a decrease in the absorbance of the blue compound. When the concentration of phoxim is between 30~240 μg/ L,the absorbance of the oxidation product of TMB at 652 nm decreases linearly with the increase of phoxim concentration. The detection limit of the method reaches 7. 33 μg/L(S/N=3),and the sensitivity is higher than those in literature. It has been successfully applied to the detection of phoxim in carrots. © 2022, Science Press (China). All rights reserved.  相似文献   

2.
In recent years, lithium-sulfur (Li-S) batteries have been considered as a promising candidate for the next generation of energy storage system due to their ultrahigh theoretical capacity (1675 mAh窑g-1) and energy density (2600 Wh窑kg-1). However, the practical application of Li-S batteries is seriously limited by their insu lating nature of sulfur, the shuttle effect of polysulfides (LiPSs), and volume expansion during charging and discharging. To overcome those disadvantages, one of the commonly methods is to infiltrate sulfur into porous conductive carbon framework, such as porous carbon, hollow carbon spheres, graphene, carbon nanotubes and some composites of the above structures to achieve the purpose of physically limiting the shuttle effect of polysulfides, thereby improving the performance of Li-S batteries. However, due to the nonpolarity of traditional carbon materials, the interaction with polar polysulfides is very weak, which cannot effectively inhibit the shuttle effect of polysulfides. Previous studies have shown that introducing heteroatom (N, S, P, B, etc.) doping into carbon matrix is a feasible method to adjust the nonpolarity of carbon materials. It is reported that the introduction of N atoms is conducive to improving the electrochemical activity. The Li-N bond formed by the interaction between N and Li+ can anchor polysulfides, effectively inhibit the dissolution of polysulfides and improve the utilization rate of sulfur. The introduction of nitrogen and sulfur heteroatoms can increase polar sites and active centers, thus, enhancing the adsorption capacity of carbon materials for polysulfides and capturing polysulfides. Therefore, ionic liquids are selected as nitrogen and sulfur sources to improve the polarity of carbon materials. In this paper, nitrogen and sulfur co-doped porous carbon (NSPC) was synthesized by using glucose as carbon source, KCl and ZnCl2 as templates, KOH as activator and ionic liquid as heteroatom source. XPS and adsorption experiments show that nitrogen and sulfur heteroatoms had been successfully introduced into NSPC, which improved the adsorption capacity of carbon materials for polysulfides, effectively alleviated the shuttle effect of polysulfides. The higher specific surface area (1290.67 m2窑g-1) could help to improve the sulfur loading. After loading 70.1wt.% sulfur into NSPC (S@NSPC) and tested as a cathode material of Li-S battery, the initial discharge capacity was 1229.2 mAh窑g-1 at 167.5 mA窑g-1, higher than the 861.6 mAh窑g-1 of S@PC, and the capacity remained at 328.1 mAh窑g-1 after 500 cycles. When the current density returned to 167.5 mA窑g-1, the reversible capacity almost went back to its initial value, which was 80% of its initial value. The good performance was mainly ascribed to both the porous structure and N, S co-dopants, which provided physical blocks and chemical affinity, respectively, for the efficient immobilization of intermediate lithium polysulfides. The results would provide an effective example in the surface chemistry and sulfur host materials design for high performance Li-S batteries. © 2021 Journal of Electrochemistry. All rights reserved.  相似文献   

3.
A novel ratio-fluorescent probe based on molecular imprinting polymer ( MIP) for the detection of sulfadiazine was prepared by using nitrogen-doped carbon quantum dots (N-CQDs) as the fluorescence response signal, silica-embedded cadmium telluride quantum dots ( CdTe QDs) as the fluorescence reference signal, sulfadiazine ( SDZ) as template molecule, acrylamide as functional monomer, N, N-methyl bisacrylamide as crosslinking agent and 2,2-Azobisisobutyronitrile as initiator. The results showed that the probe has a core-shell structure and fluorescence sensitive to SDZ, by the characterization of scanning electron microscopy, transmission electron microscopy, and fluorescence spectrophotometer. Under the wavelength of 360 nm, the ratio-fluorescent signal of probe showed a linear response with SDZ concentration in the range of 0-100 μmol / L with the detection limit of 11 nmol / L. Also, the ratio-fluorescent probe was applied to the detection of SDZ with a recovery of 92. 0%-95. 1% and relative standard deviation (RSD) of 3. 6% in real water samples. © 2022, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

4.
田秦秦  张佳  陈峙  何炜  张生勇 《应用化学》2022,39(8):1177-1189
Posaconazole,as the second generation of triazole antifungal drugs,has a wide antifungal spectrum and strong antibacterial activity. It is widely used in clinical practice. However,it has been eight years since its publication before it is approved in China. In order to better understand posaconazole,a first-line drug with great clinical demand, this paper summarizes the pharmacokinetics, pharmacological properties,clinical application and synthetic route of posaconazole in the literature at home and abroad. It is hoped that it can fill the gap in the domestic API market,break the current situation that the API is completely dependent on import,and provide a useful reference for the industrial R & D. © 2022, Science Press (China). All rights reserved.  相似文献   

5.
Nitrogen-doped carbon dots (N-CDs) were prepared by one-step hydrothermal synthesis with pomegranate seeds as the carbon source and urea as the nitrogen source. Observed by transmission electron microscopy (TEM), average particle size of N-CDs was 20 nm. Observed by atomic force microscopy (AFM), the thickness of N-CDs was 0. 6-1. 4 nm. Fourier transform infra-red (FT-IR) confirmed the presence of water-soluble functional groups such as amino groups on the surface of N-CDs. With the prepared N-CDs as the target fluorophore, Hg2 + can efficiently bind to the surface of N-CDs to form a complex, and achieve static quenching. The addition of tiopronin can bind the Hg2 + in the complex to make the Hg2 + detach from the surface of N-CDs and realize fluorescence recovery. The nano fluorescence switch constructed in this work is more accurate and sensitive than the traditional detection method. The optimum conditions were determined by optimizing the pH value, reaction time, the dosage of N-CDs and Hg2 +. The relative deviation (RSD) was 4. 7%, and the detection limit was 0. 2 μmol/L. The method was used to determine the content of tiopronin in human serum samples with the recoveries of 97. 2%-101. 3%. © 2022, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

6.
A novel amphiphilic copolymer,dipropenoxystyrene anthracene and acrylic acid copolymer(BASA-AA) was designed and synthesized based on divinyl anthracene. The polymer self-assembled rapidly in water to create polymer nanoparticles(BASA-AA NPs)with a uniform size of 45 nm,no dye leakage,and great brightness(Φ= 36%). Because of the enormous number of carboxyl groups on the surface of the particles,it can disperse extremely well in water,and can be used for the rapid detection of copper ion and cysteine(Cys)in pure water, with the limit of detection of 45 nmol/L. The fluorescent intensity of the nanoparticles will be greatly reduced after the introduction of copper ion,realizing the detection of copper ion with high selectivity and sensitivity. A composite probe made of BASA-AA NPs and copper ion can detect Cys in the range of 0.1-10 µμmol/L,with the detection limit of 84 nmol/L,due to the high binding capacity of the sulfhydryl group and copper ion. The method is simple and rapid in material synthesis and preparation,and shows high selectivity and sensitivity in pure water. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

7.
Redox graphene-MXene(rGO-MXene) nanocomposites were prepared by ion polymerization and used to construct a highly sensitive electrochemical sensor for baicalin(BA) detection. The synergistic effect of rGO and MXene increased the specific surface area and electron transport capacity of the electrode, and significantly enhanced the electrochemical response of BA. The cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of BA on the sensor. Under the optimal conditions, the peak current exhibited a good linear relationship with BA concentration in the range of 0. 05-10 μmol / L, and the limit of detection was as low as 28 nmol / L. The method was applied to analyze traditional Chinese medicine preparations containing baicalin, such as Qingkailing Capsule and Sanhuang Tablets with good accuracy and spiked recovery. The results were highly consistent with those of high performance liquid chromatography, providing a technical means for the rapid and sensitive detection of traditional Chinese medicine preparations. © 2022, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

8.
Lithium-ion batteries (LIBs)have attracted wide attention because of their broad prospects in electric vehicles. However,the safety problems and low multiplier performance of the commercial polyolefin separator limit their further development,due to the poor dimensional thermal stability and low electrolyte absorption rate. Poly(ether ether ketone)(PEEK)and carbon nanotube(CNT)are compounded to coat on polypropylene (PP) to prepare Janus composite separator (PP@C) through the phase inversion method. PP@C composite separator does not deform at 180 ℃ for 0. 5 h(only slight deformation),illustrating excellent thermal stability. The electrolyte absorption rate of PP@C2 is 193. 8%. The electrolyte uptake rate of the PP@C2 composite membrane was 193. 8%,which was 64. 5% higher than the PP membrane,showing a superduper electrolyte permeability. As a result,the specific discharge capacity of LIBs assembled with PP@C2 composite separator is 157. 6 mA·h/g at 0. 2 C and 129. 8 mA·h/g at 2 C,showing good rate performance with the capacity recovery rate of more than 99%. This might be attributed to the ultra-high thermal stability of PEEK,the good affinity of the electrolyte,the high conductivity of CNT,as well as the uniform dispersion of Li+ ,so that the separator can have excellent electrochemical performance while improving safety. © 2022, Science Press (China). All rights reserved.  相似文献   

9.
Formyldeoxycholic acid modified Fe3O4 nanoparticles(FDCA-MNPs)have been successfully constructed. The structure,morphology and magnetic properties of FDCA-MNPs are characterized by Fourier transform infrared spectroscopy(FT-IR),transmission electron microscopy(TEM)and vibrating sample magnetometer. Oxytetracycline(OTC)is used as a model drug to evaluate the drug loading and release behaviors of FDCA-MNPs. The maximum loading of OTC is 59. 7 mg/g,and the loading behavior follows Freundlich adsorption balance equations with multilayer adsorption.Furthermore,FDCA-MNPs@OTC shows a higher release rate at pH=9 (11. 8%)than that of pH=7(8. 8%). The bacteriostatic activities of FDCA-MNPs,OTC,FDCA-MNPs@OTC against E. coli are compared in vitro. The results show that FDCA-MNPs have no inhibition-activity for E. coli, meanwhile,FDCA-MNPs@OTC displays better sterilization ability than OTC at the same concentration. The minimum antibacterial concentration is 3 μg/mL,and the antibacterial rate reaches 97. 8%. It is proved that the synergistic effect of drug carrier and drugs reveals good antibacterial properties and reduce the dosage of antibiotics. © 2022, Science Press (China). All rights reserved.  相似文献   

10.
Silica nanosheets (SiO2NSs)were successfully assembled on titanium (Ti)wires by sol-gel method. TiO2 nanosheets (TiO2NSs)were grown in situ on Ti wires using anodic oxidation in a fluoride-containing electrolyte to obtain Ti@TiO2NSs. The Ti@TiO2NSs@SiO2NSs fibers were obtained by coating Ti@TiO2NSs with SiO2NSs. It was characterized by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The fibers were used for solid-phase microextraction of ultraviolet absorbers (UVFs). Under the optimized conditions, six UVFs presented good linearity with the correlation coefficients (R2) greater than 0.999, and the limits of detection (LODs)ranged from 9 to 59 ng/L. The intra-day and inter-day relative standard deviations (RSDs) were from 4.3% to 5.1% and 4.6% to 5.8% for a single fiber at the spiked level of 25 μg/L, respectively. The developed method was successfully applied to the selective enrichment and determination of target UVFs in environmental water samples with recoveries from 93.2% to 108.1% and RSDs from 4.5% to 7.1%. Moreover, the fiber can be fabricated in a precisely controllable manner and is stable for at least 200 extraction and desorption cycles. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

11.
刘琳  何华锋 《应用化学》2022,39(10):1579-1585
The low-k dielectric materials with their low mechanical strength and high porosity for advanced IC processes pose great challenges in barrier CMP slurries, requiring favorable advantages in high removal rate, adjustability, lower surface defects and improved edge over erosion (EOE). In this paper, the effects of polyether amines on the removal rate and defects toward low-k materials are studied. The results show that the removal rate of low-k material decreases by 68%~85%, the number of residual particles on the surface of low-k material decreases by 80%, and EOE decreases by 2/3, which meets the requirements of advanced technology for barrier CMP slurries. © 2022, Science Press (China). All rights reserved.  相似文献   

12.
A new type of fluorescent probe Na-pHNO was synthesized for the simultaneous detection of NO and pH based on naphthalimide derivative. The probe had good fluorescence property in mixture solution of 99% phosphate buffer solution(PBS)and 1% dimethyl sulfoxide(DMSO)solution. It can produce a yellow-green emission peak at 544 nm,and the fluorescence intensity can be enhanced with the increase of NO concentration or the decrease of pH. The probe Na-pHNO displayed good selectivity,high sensitivity,and strong anti-interference towards NO,exhibiting good fluorescence reversibility at pH 5.5-8.5. The spectral studies showed that the probe Na-pHNO exhibited weak fluorescence due to a dual photoinduced electron transfer(PET)effect. After interacting with NO or pH,the dual PET inhibitory effect occurred,and the fluorescence intensity was significantly enhanced. The fluorescence imaging of probe Na-pHNO in HeLa cells showed that it could realize the visual monitoring of the changes of intracellular pH and NO concentration. The probe has been successfully applied to fluorescence imaging of Caenorhabditis elegans. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

13.
:Based on the pre-column derivatization of monosaccharides with 1-phenyl-3-methyl-5-pyrazolone,the fingerprints of polysaccharide hydrolysate monosaccharides in the extract of Mesona chinensis Benth was established using reversed-phase high performance liquid chromatography (HPLC) gradient elution/UV detection technology,which was used for the analysis of the components and content of polysaccharide hydrolyzed monosaccharides in the aqueous extract of Mesona chinensis Benth,and eight monosaccharide components including ribose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,xylose and arabinose were identified. Similarity analysis,cluster analysis,principal component analysis of the HPLC fingerprints of monosaccharide components were carried out,and the changes in the contents of galactose, galacturonic acid and glucose monosaccharide components in various samples were clarified. Regional differences lead to differences in cluster analysis,and there are certain differences in the content and distribution of monosaccharide components produced by polysaccharide hydrolysis in Mesona chinensis Benth collected from different origins. The method can provide a potential technology for characterizing monosaccharide components of the polysaccharide in aqueous extract of Mesona chinensis Benth. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

14.
A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was developed for the determination of perfluorooctane sulfonic acid (PFOS)in cosmetics. The cosmetic samples were extracted with methanol by ultrasonication,and PFOS was quantified by HPLC-MS/MS. The samples were detected in negative multiple reaction monitoring(MRM)mode using an Agilent Poroshell 120 EC-C18 (100 mm× 2.1 mm,2.7 µμm)column with a gradient elution using 0.1% formic acid aqueous solution(A)-methanol(B)as the mobile phase. The results showed that the linearity of PFOS was good in the range of 1-100 µμg/L with the correlation coefficient r2 larger than 0.9998;the limits of detection and limits of quantification were 0.015 and 0.050 mg/kg,respectively. The average recoveries were 98.7%-112.5%,and the relative standard deviations (RSDs)were less than 5%. The method is suitable for the determination of PFOS in cosmetics. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

15.
磷酸二酯酶5抑制剂(PDE5i)用于治疗勃起功能障碍和肺动脉高压等疾病。因PDE5i类药物种类繁多,理化性质各异,在体内代谢迅速且具有多种代谢途径,故生物样本检验难度大。本文介绍了PDE5i类药物及其代谢物,总结了生物样本中该类物质的沉淀蛋白法、液-液萃取法、固相萃取法和固相微萃取法等前处理方法,综述了高效液相色谱法、液相色谱质谱联用法、荧光光谱法和电化学分析法等检测方法,展望了PDE5i及其代谢物分析的未来发展方向,以期为PDE5i的药物监测和法庭科学毒物检验提供参考。  相似文献   

16.
By hydrothermal synthesis, silver nanoparticles (AgNPs) arranged on single-walled carbon nanotubes (SWCNTs) uniformly, and a SiO2/CNTs/AgNPs surface enhanced Raman scattering (SERS) substrate with composite open structure was prepared. The synthesized SiO2/CNTs/AgNPs were characterized by transmission electron microscopy (TEM. Using rhodamine 6G(R6G) as the probe molecule, the enhancement factor (EF) was 1.23×108, and the standard deviation was 2.31. Taking the phenol red, a common water pollutant, as the practical sample, the concentration of phenol red in the range of 1×10-4 -1×10-10 mol/L had a great exponential fitting relationship with its Raman signal intensity at 1153 cm-1 and 1441 cm-1, and the correlation coefficient (R2) was 0.99991. The substrate can realize the qualitative and quantitative detection of practical samples. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

17.
By preparing nano-CeO2 (CeO2) and reduced graphene oxide (RGO), an electrochemical sensor based on CeO2/RGO composite was constructed for the detection of histamine. The morphology and structure of the composites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical behavior of histamine on the sensor was studied by cyclic voltammetry (CV), and the conditions such as the type proportion and addition amount of the composite scanning rate and buffer pH were optimized. The results showed that the optimal conditions were as follows: The mass ratio was m(CeO2): M(RGO)=1: 0.25, the addition amount of composite material was 10 μL, the scanning rate was 300 mV/s and the pH of buffer solution was 8. A good linear relationship was observed between the peak current and the concentration of histamine in the range of 0.25–100 mg/L with the detection limit of 0.16 mg/L. The CeO2/RGO/GCE electrochemical sensor has been applied to the determination of histamine in fish samples with the spiked recoveries of 98.4% −104%. The method can be used to determine histamine content in fish products. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

18.
The oxidase-like activity of cobalt oxyhydroxide (CoOOH) nanosheets is inhibited by arsenic (V) in the system, thereby attenuating the oxidation of p-phenylenediamine (PPD) by CoOOH nanosheets, and changing the absorbance of the solution. Based on this principle, and the fluorescence inner filter effect (IFE) of p-phenylenediamine oxide (oxPPD) on the dye acridine orange (AO), a colorimetric and fluorescence dualmode method for the quantitative detection of As(V) was established. The variation of absorbance and fluorescence intensity of As(V) with different concentrations was investigated, and the effects of the concentrations of CoOOH nanosheet and PPD, pH of buffer solution, and temperature of reaction were optimized. The results showed that under the optimized conditions, the concentration of As(Ⅴ) had a good linear relationship with the corresponding signal intensity, and the detection limits of colorimetric and fluorescence method were 5 and 10 nmol/L, respectively. The method has been used for the determination of arsenic(V) in lake water located the city center. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

19.
张万年  于芳  赵杉林  张志强  何宇鹏 《应用化学》2022,39(12):1803-1817
Recently,the use of computational methods such as Molecular Dynamics(MD)simulations and Hansen Solubility Parameters (HSPs)to study the behavior of small molecule gelators has attracted much attention. MD simulation is a computational method based on classical mechanics and is one of the preferred techniques for understanding the process of small molecule gelators. The MD simulation can more accurately analyze the gelation trend or assembly behavior of small molecule gelators,dynamically and graphically display the self-assembly process,effectively reveal the relationship between the structure of small molecule gelators and related gelation behavior,and quantitatively analyze non-covalent bond interactions such as hydrogen bonds,π-π stacking,van der Waals interactions,ionic bonding and solvophobic interactions. By performing molecular dynamics simulations on known gelators/non-gelators,parameters related to gelation behavior in the simulated data are extracted,and the linear correlation is measured by fitting the Pearson correlation coefficient to finally predict the gelation behavior of a certain class of small molecules. On the other hand,the empirical model developed according to the HSPs is the most representative,which consists of the energy of dispersion interaction(δd),the energy of polar interaction(δp)and H-bonding energy(δh )between molecules. These three parts determine the coordinate point of the three-dimensional space(Hansen space). According to the range of the point,it can be determined whether the organic small molecule can form a gel in a specific solvent. In this paper,representative works published recently in the field of organic small molecule gels by using MD simulations and empirical models are reviewed. Some comments on the assembly behavior of gelators,the regulation and prediction of non-covalent bond interactions on gelation ability are made. © 2022, Science Press (China). All rights reserved.  相似文献   

20.
A method for the untargeted screening and quantitative analysis of drug residues in bean sprouts by ultra performance liquid chromatography-quadrupole/ orbitrap high resolution mass spectrometry (UPLC-QOrbitrap HRMS) was developed. In the process of screening, the samples were extracted by acetonitrile and the data were gathered via the full MS-ddMS2 mode. In the absence of standards, qualitative analysis was carried out according to the exact mass number of precursor ions and secondary fragment ions information combined with the database. The optimized dispersive solid-phase extraction (d-SPE) method was used to purify the samples. 9 compounds in bean sprouts were screened and quantified on the basis of the peak areas of the precursor ions. 9 compounds showed good linear relationships (R2>0.990) in the linear concentration ranges. The limits of detection of this method were between 2.0-5.0 μg/kg. The recoveries of 9 compounds at three spiked levels of 5, 10, 50 μg/kg ranged from 80.1% to 111.1%, and the relative standard deviations were less than 15%. © 2023, Youke Publishing Co.,Ltd. All rights reserved.  相似文献   

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