MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 4
·1-8
·
IF 5.705
Liu Xinnan,Zhang Wentao,Huang Lunjie,Hu Na,Liu Wei,Liu Yingnan,Li Sihang,Yang Chengyuan,Suo Yourui,Wang Jianlong
A method is described for the rapid fluorometric determination of dopamine (DA) by using molybdenum disulfide quantum dots (MoS 2 QDs) that were fabricated via an ammonium hydroxide etching method. The probe has a fluorescence (with excitation/emission peaks at 267/380 nm) that is quenched by DA with high selectivity over various interferences. This is attributed to a reaction that occurs between DA and the molybdate ions in pH 9 solutions of MoS 2 QDs. The formation of organic molybdate complexes and of dopamine-quinone results in strong quenching of the fluorescence of the QDs which is due to both electron transfer and an inner filter effect. Under the optimum conditions, the assay works in the 0.1–100 μM DA concentration range, with two linear ranges and a 10 nM detection limit. The method was applied to the determination of DA in spiked artificial urine samples, where it gave recoveries ranging from 97.6 to 102.2%, demonstrating that the method a promising tool for rapid and selective detection of DA.
MoS 2 QDs are facilely synthesized via the etching effect of ammonium hydroxide for highly selective fluorometric detection of dopamine.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION SCIENCE AND TECHNOLOGY
·
2014
·
IF 1.2
Jie-Ping Fan,Lie Li,Ze-You Tian,Chun-Fang Xie,Yuan Xue,Yan-Long Xie,Rui Xu,Yu Qin,Xue-Hong Zhang,Jian-Hang Zhu
Uniformly sized synephrine molecularly imprinted polymer (MIP) microparticles were prepared via precipitation polymerization. The presence of the template, the amount of monomer, crosslinker, and porogenic solvent could affect the size distribution and morphology of the polymers. The pseudo-second-order kinetic model could provide a better correlation for the adsorption than the pseudo-first-order model. The intraparticle diffusion study showed that the sorption involved intraparticle diffusion, but that was not the only rate-controlling step. The equilibrium data better fit the Freundlich model than the Langmuir model. The Scatchard plot of MIPs revealed MIPs had two groups of sites with different affinities. Subsequent recognition selectivity experiments demonstrated preferential structural selectivity for synephrine with respect to other structurally similar compounds (i.e., octopamine and tyramine). Compared with the bulk MIP of SYN, the SYN MIP microparticles in this work had higher adsorption selectivity and capacity due to their smaller particle sizes; moreover, the precipitation polymerization was time-saving due to not using a crash-and-sieve process.
✓ 已验证
产品关联
DOI
高影响因子
BIOMEDICAL CHROMATOGRAPHY
·
2015
·Vol. 29
·期 11
·1737-1743
·
IF 1.723
Xue-jia Zhai,Fen Chen,Chao-ran Zhu,Yong-ning Lu
Many amino acid neurotransmitters in urine are associated with chronic stress as well as major depressive disorders. To better understand depression, an analytical LC-MS/MS method for the simultaneous determination of 11 underivatized neurotransmitters (4-aminohippurate, 5-HIAA, glutamate, glutamine, hippurate, pimelate, proline, tryptophan, tyramine, tyrosine and valine) in a single analytical run was developed. The advantage of this method is the simple preparation in that there is no need to deconjugate the urine samples. The quantification range was 25–12,800 ng mL −1 with >85.8% recovery for all analytes. The nocturnal urine concentrations of the 11 neurotransmitters in chronic unpredictable mild stress (CUMS) model rats and control group ( n = 12) were analyzed. A series of significant changes in urinary excretion of neurotransmitters could be detected: the urinary glutamate, glutamine, hippurate and tyramine concentrations were significantly lower in the CUMS group. In addition, the urinary concentrations of tryptophan as well as tyrosine were significantly higher in chronically stressed rats. This method allows the assessment of the neurotransmitters associated with CUMS in rat urine in a single analytical run, making it suitable for implementation as a routine technique in depression research. Copyright © 2015 John Wiley & Sons, Ltd.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2017
·
IF 6.32
Jiahui Zhao,Xingfu Bao,Shuang Wang,Shasha Lu,Jian Sun,Xiurong Yang
As a well-known copper-containing oxidase, tyrosinase has been anticipated to serve as the biomarker of skin diseases. We describe here an exquisite label-free fluorescent and colorimetric dual-readout assay of its activity, inspired by the specific oxidation ability of monophenolamine substrates to catecholamines and a unique fluorogenic reaction between resorcinol and catecholamines. By employing commercially available tyramine as the model substrate (dopamine as the product), it is found that the tyrosinase-incubated tyramine solution exhibits obvious pale yellow with intense blue fluorescence in the presence of resorcinol and O2, where the absorbance and fluorescence intensity are directly related to the concentration of added tyrosinase (i.e., the amount of conversion of tyramine to dopamine). The overall process of sensing tyrosinase activity takes less than 100 min at ambient temperature and pressure conditions with exceedingly simple operation procedure, explicit response mechanism, and formation of fluorophore with high quantum yield from scratch. Furthermore, such a convenient, rapid, cost-effective, and highly sensitive dual-readout assay exhibits promising prospect for the tyrosinase activity in extensive bioassays and clinic research as well as in screening potential tyrosinase inhibitors.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Cellular and Infection Microbiology
·
2016
·
IF 5.218
Dong Yuhao,Liu Jin,Pang Maoda,Du Hechao,Wang Nannan,Awan Furqan,Lu Chengping,Liu Yongjie
The growth-stimulating effects of catecholamine stress hormones have been demonstrated in many pathogens. However, catecholamine-induced growth and its underlying mechanisms remain poorly understood in Aeromonas hydrophila. The present study sought to demonstrate that norepinephrine (NE), epinephrine (Epi), dopamine (Dopa), and L-dopa stimulate the growth of A. hydrophila in iron-restricted media containing serum. NE exhibited the strongest growth stimulation, which could be blocked by adrenergic antagonists. Furthermore, it was demonstrated that NE could sequester iron from transferrin, thereby providing a more accessible iron source for utilization by A. hydrophila. The deletion of the amoA gene associated with amonabactin synthesis revealed that the amonabactin siderophore is not required for NE-stimulated growth. However, the deletion of the TonB2 energy transduction system resulted in the loss of growth promotion by NE, indicating that a specific TonB-dependent outer membrane receptor might be involved in the transport of iron from transferrin. Collectively, our data show that catecholamine sensing promotes the growth of A. hydrophila in a manner that is dependent on the TonB2 energy transduction system.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2016
·
IF 1.78
Dan-dan Yang,Riu Wang,Jin-long Zhu,Qi-yue Cao,Jie Qin,Hai-liang Zhu,Shao-song Qian
Three novel complexes, [Cu( L ) 2 (H 2 O)]( 1 ), [Zn( L ) 2 (H 2 O) 2 ]·CH 3 OH·1.5H 2 O( 2 ), and [Ni( L ) 2 (H 2 O) 1.8 ]·CH 3 OH·1.2H 2 O ( 3 ) (HL = 2-{4-[bis(4-fluorophenyl)methyl]pipera-zin-1-yl} acetic acid), were synthesized and structurally determined by single-crystal X-ray diffraction. Molecular docking study preliminarily revealed that complex 1 had potential Monoamine oxidase B inhibitory activity. All acquired compounds were tested against rat brain MAO-B in vitro. In accordance with the result of calculation, it showed complex 1 (IC 50 = 1.85 ± 0.31 μ M) have good inhibitory activity against MAO-B at the same micromolar concentrations with positive control Iproniazid Phosphate (IP, IC 50 = 7.59 ± 1.17 μ M). These results indicated that complex 1 was a potent MAO-B inhibitor.
✓ 已验证
产品关联
DOI
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Xueli Wang,Xueting Liu,Chunmei Sun,Yanwei Cheng,Zhen Li,Shuyi Qiu,Yongguang Huang
Daocai is a traditional salted pickle in the southeastern region of Guizhou with a unique aroma, color, and taste. The quality of Daocai is greatly influenced by the fermentation temperature. In this study, high-throughput sequencing and headspace-gas chromatography-ion mobility spectrometry were used to investigate the changes in microbial community succession and volatile flavor compounds during Daocai fermentation under temperature-controlled (D group) and non-temperature-controlled (C group).We found that the predominant genera in the C group samples were Latilactobacillus (40.57 %), Leuconostoc (21.25 %), Cystofilobasidium (22.12 %), Vishniacozyma (23.89 %), and Leucosporidium (24.95 %), whereas Weissella (29.39 %), Lactiplantibacillus (45.61 %), Mucor (68.26 %), and Saccharomyces (23.94 %) were the predominant genera in the D group. A total of 92 VFCs were detected in Daocai samples, including 5 isothiocyanates, 16 esters, 14 alcohols, 24 aldehydes, 17 ketones, 3 acids, 2 pyrazines, 1 pyridines, 1 thiazoles, 3 furans, 4 alkenes, and 2 nitriles. Further analysis revealed Latilactobacillus , Leuconostoc , Lactococcus , Cystofilobasidium , Leucosporidium , Holtermanniella , and Dioszegia as key bacteria involved in flavor formation. They are closely related to the formation of flavors such as aldehydes, furans, pyridines, and alkenes. This study contributes to our understanding of the relationship between bacterial communities and the flavor formation during Daocai fermentation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CONTROL
·
2024
·
IF 5.6
Xia Xu,Xin Liu,Yixing Qiu,Yufan Song,Xuxia Zhou,Yuting Ding
The accurate determination of histamine in fish is imperative for food safety, given the toxic nature of this biogenic amine . This study presents an innovative colorimetric aptasensor for the ultrasensitive detection of histamine in fish, utilizing nanozymes based on magnetic metal-organic frameworks coated with Pt nanoparticles (Fe 3 O 4 @MOF@Pt), which exhibit high peroxidase-like catalytic activity, magnetism, and superior optical properties. The surface of Fe 3 O 4 @MOF@Pt nanozymes were modified with DNA strands complementary to the histamine aptamer , creating effective colorimetric probes. In the presence of histamine, these colorimetric probes compete with histamine molecules for aptamer binding on the enzyme plate. Color development is triggered by adding a TMB and H 2 O 2 substrate solution to the enzyme plate. This competitive binding-based aptasensor allows for rapid and accurate histamine quantification within a linear range of 10 pM to 10 μM, and a notable detection limit of 6.23 pM. Furthermore, the sensor demonstrated excellent specificity, distinguishing histamine from l -histidine and other biogenic amines. Tested on mackerel samples, the aptasensor showed spiked recoveries of 91.4%–109.6%, validating its practical applicability. This sensor offers an ultrasensitive, specific, and reusable tool for histamine detection, representing a significant advancement in ensuring the safety of fish products.
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Yanan Liu,Jiacheng Gan,Fei Chen,Jian Chen,Huan Li,Yanbo Wang
Dual-enzyme co-embedded materials have shown high potential for achieving efficient detection due to the convenience of two-enzyme cascade reactions. Herein, we developed a dual-enzyme hybrid microsphere (HM) based biosensor to detect diamines (histamine was included for ease of description) in aquatic products. The HM was made from diamine oxidase , horseradish peroxidase , and copper phosphate through the biomineralization method. Under optimal conditions, the system displayed linear color response to histamine of different concentrations ranging from 0 to 200 μg/mL. The detection limit of histamine was 0.15 μg/mL, showing higher sensitivity than the two-step free enzyme assay . Moreover, the detection system exhibited good specificity to diamines. The method was used to detect diamines in commercial samples, and the results were compared with those measured by the high-performance liquid chromatography method. Overall, the proposed assay exhibited high potential in diamine quantification and was readily extended to other cascade enzymatic reaction-based detection strategies.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Synthetic Biology
·
2024
·
IF 3.7
Jiao Feng,Runyuan Jin,Shasha Cheng,Hui Li,Xin Wang,Kequan Chen
In this study, we designed an artificial pathway composed of tyramine β-hydroxylase (TBH) and phenylethanolamine N-methyltransferase (PNMT) for the biosynthesis of both octopamine and synephrine. As most TBH and PNMT originate from eukaryotic animals and plants, the heterologous expression and identification of functional TBH and PNMT are critical for establishing the pathway in mode microorganisms like Escherichia coli. Here, three TBHs were evaluated, and only TBH from Drosophila melanogaster was successfully expressed in the soluble form in E. coli. Its expression was promoted by evaluating the effects of different expression strategies. The specific enzyme activity of TBH was optimized up to 229.50 U·g–1, and the first step in the biosynthetic pathway was successfully established and converted tyramine to synthesize 0.10 g/L of octopamine. Furthermore, the second step to produce synephrine from octopamine was developed by screening PNMT, enhancing enzyme activity, and optimizing reaction conditions, with a maximum synephrine production of 2.02 g/L. Finally, based on the optimization of the reaction conditions for each individual reaction, the one-pot cascade reaction for synthesizing synephrine from tyramine was constructed by combining the TBH and PNMT. The synthetic synephrine reached 30.05 mg/L with tyramine as substrate in the two-step enzyme cascade system. With further optimization and amplification, the titers of octopamine and synephrine were increased to 0.45 and 0.20 g/L, respectively, with tyramine as substrate. This work was the first achievement of the biosynthesis of octopamine and synephrine to date.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Lian Xia,Feng Luo,Xiaojuan Niu,Yue Tang,Yuangen Wu
Pb(II) is a prevalent heavy metal ion classified as a 2B carcinogen. Excessive intake of Pb(II) in the human body can damage the central nervous system, kidneys, liver, and immune system, leading to permanent brain damage, anemia, and cancer. Colorimetry can be applied to rapidly determine Pb(II) residues, but there are still many challenges in the accuracy and sensitivity of detection. Based on the inhibitory impact of Pb(II) on the oxidase-like activity of octahedral silver oxide (Ag 2 O), a colorimetric sensor with smartphone-assisted analysis for the Pb(II) detection was first developed. Herein, it has been found that Pb(II) can adsorb onto the surface of octahedral Ag 2 O, hindering the production of O 2 − in the reaction system. This ultimately results in the suppression of oxidase-like activity, leading to a lighter purple appearance of the colorimetric reaction solution. The sensor exhibits a high degree of sensitivity and a limit of detection (LOD) for Pb(II) was calculated as 2.2 μg L −1 . Hence, the developed colorimetric sensor with high sensitivity, excellent specificity, and high tolerance to sodium ions is hopeful to have practical applications in Pb(II) detection in environmental water samples. Moreover, the sensor will provide a novel strategy for heavy metal ion detection and other substances.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Hao-Xin Niu,Tian-Mo Yang,Xin Wang,Ping Zhang,Wenwen Guo,Lei Song,Yuan Hu
Epoxy thermosets are used in many fields because of their outstanding properties. However, commercial epoxy thermosets are flammable, so epoxy resins with excellent flame retardant properties need to be prepared. In recent years, carbon fiber epoxy composites have been widely used in aerospace and other high-tech fields due to their high strength and excellent performance. With the increased use of carbon fiber epoxy composites, the recycling of carbon fibers is an important issue. Herein, a bio-based epoxy vitrimer (TVEP/DFDA) containing a Schiff base structure was successfully prepared by utilizing vanillin, tyramine and furfurylamine. Moreover, carbon fiber epoxy composites (CF-TVEP/DFDA) were successfully prepared. The TVEP/DFDA composite has better mechanical properties than DGEBA/DDM and excellent flame-retardant performance. The limiting oxygen index (LOI) of TVEP/DFDA was 28.5%, and TVEP/DFDA achieved a UL-94 V-0 rating. Heat hazards and smoke hazards are sources of danger in fires. According to the cone calorimetry test, compared with those of DGEBA/DDM, the heat release rate, total heat release and total smoke production of TVEP/DFDA decreased by 73.9%, 52.6% and 56.6%, respectively. The significantly reduced heat and smoke production indicate that TVEP/DFDA has a lower combustion intensity and better fire safety than DGEBA/DDM. CF-TVEP/DFDA also exhibited excellent flame-retardant performance, with a high LOI of up to 45% and a UL-94 V-0 rating. However, the CF-DGEBA/DDM cannot pass the vertical burning test. TVEP/DFDA has excellent stability under different solvents and can be degraded under acidic conditions. This work describes a strategy for recycling carbon fibers by immersion in a hydrochloric acid solution. The recycled carbon fibers exhibit surface morphologies, chemical structures and mechanical properties similar to those of virgin carbon fibers.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）