JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
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2020
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IF 3.255
Rahul Narayanan,Xiaowei Song,Hao Chen,Richard N. Zare
Polytetrafluoroethene, commonly known as Teflon, is a plastic famous for its inertness, strength, and nonstick properties, allowing its repeated use in many applications. We report the use of a triangularly cut Teflon substrate to take the place of paper in a form of spray mass spectrometry. A conducting wire (gold) at high potential (positive or negative) makes contact with a drop of the liquid sample at the apex of the triangle, causing a spray of droplets to be directed toward the heated inlet of a mass spectrometer. Saccharides, drugs, illegal additives, peptides, proteins, bilirubin, and vancomycin give mass spectra with high signal-to-noise (S/N) ratios, allowing detection at the nanogram per milliliter (ng/mL) level. Examination of each of these analytes demonstrates that Teflon spray is several orders of magnitude more sensitive than paper spray under the same conditions. Teflon spray ionization mass spectrometry is applied to the metabolomic and lipidomic profiling of biological fluid samples. Detection of polycyclic aromatic hydrocarbons is achieved with Teflon spray at 10 μg/mL concentrations. These experiments show the advantage of using Teflon over a normal paper substrate in detecting many environmentally and biologically relevant systems with high sensitivity and S/N ratio.
研究领域:
分析化学
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环境科学
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生物医学
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2014
·Vol. 15
·期 1
·774-786
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IF 2.339
Wei Qian,Deng-Guang Yu,Ying Li,Yao-Zu Liao,Xia Wang,Lu Wang
This study reports a new type of drug-loaded core-shell nanofibers capable of providing dual controlled release with tunable dose in the second phase. The core-shell nanofibers were fabricated through a modified coaxial electrospinning using a Teflon-coated concentric spinneret. Poly(vinyl pyrrolidone) and ethyl cellulose were used as the shell and core polymer matrices respectively, and the content of active ingredient acetaminophen (APAP) in the core was programmed. The Teflon-coated concentric spinneret may facilitate the efficacious and stable preparation of core-shell nanofibers through the modified coaxial electrospinning, where the core fluids were electrospinnable and the shell fluid had no electrospinnability. The resultant nanofibers had linear morphologies and clear core-shell structures, as observed by the scanning and transmission electron microscopic images. APAP was amorphously distributed in the shell and core polymer matrices due to the favorite second-order interactions, as indicated by the X-ray diffraction and FTIR spectroscopic tests. The results from thein vitrodissolution tests demonstrated that the core-shell nanofibers were able to furnish the desired dual drug controlled-release profiles with a tunable drug release amount in the second phase. The modified coaxial electrospinning is a useful tool to generate nanostructures with a tailored components and compositions in their different parts, and thus to realize the desired functional performances.Keywords:modified coaxial electrospinning;core-shell nanofibers;dual drug release;Teflon-coated spinneret;tunable dose
研究领域:
材料科学
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药学
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
Nature Communications
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2022
·Vol. 13
·期 1
·1-9
·
IF 17.694
Wang Ziming,Berbille Andy,Feng Yawei,Li Site,Zhu Laipan,Tang Wei,Wang Zhong Lin
Mechanochemistry has been studied for some time, but research on the reactivity of charges exchanged by contact-electrification (CE) during mechanical stimulation remains scarce. Here, we demonstrate that electrons transferred during the CE between pristine dielectric powders and water can be utilized to directly catalyze reactions without the use of conventional catalysts. Specifically, frequent CE at Fluorinated Ethylene Propylene (FEP) - water interface induces electron-exchanges, thus forming reactive oxygen species for the degradation of an aqueous methyl orange solution. Contact-electro-catalysis, by conjunction of CE, mechanochemistry and catalysis, has been proposed as a general mechanism, which has been demonstrated to be effective for various dielectric materials, such as Teflon, Nylon-6,6 and rubber. This original catalytic principle not only expands the range of catalytic materials, but also enables us to envisage catalytic processes through mechano-induced contact-electrification.
研究领域:
环境科学
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化工工程
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催化
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机械工程
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DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2022
·
IF 9.136
Xiaodong Cui,Pengcheng Li,Hua Lei,Chang Tu,Dongliang Wang,Zhu Wang,Wanping Chen
Many piezoelectric nanomaterials have recently been revealed an attractive capability to degrade organic pollutants through utilizing mechanical energy via a tribocatalytic mechanism. Presently we have explored tribocatalytic degradation of organic pollutants for TiO 2 nanoparticles. While degradation of organic dyes was observed for TiO 2 nanoparticles under ordinary magnetic stirring, the degradation was greatly enhanced when the magnetic stirring was modified through using Teflon magnetic rotating disks, which are circular Teflon disks with a cross-shaped groove on one side and magnets mounted on the other side. With TiO 2 nanoparticles under the modified magnetic stirring, as much as 99.7% of 40 mg/L Rhodamine B and 94.7% of 20 mg/L Methyl violet were degraded after 200 min, and 93.1% of 20 mg/L Methylene blue was degraded after 250 min, which are highly outstanding among catalytic dye degradations by metal oxide nanoparticles. Active radicals were detected through fluorescence spectroscopy and electron paramagnetic resonance spectroscopy for TiO 2 nanoparticles under magnetic stirring, which supports a tribocatalytic mechanism for the dye degradations. These results suggest that tribocatalysis can be an appealing technology to utilize mechanical energy for environmental remediation, especially in areas of insufficient solar energy.
研究领域:
环境科学
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纳米技术
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催化
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污染控制
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2022
·
IF 12.545
Huibing Li,Xianming Liu,Fengjiao Zhu,Dachuan Ma,Chunyue Miao,Haoran Su,Jiu Deng,Haiyue Ye,Hongyu Dong,Xue Bai,Yong Luo,Bingcheng Lin,Tingjiao Liu,Yao Lu
Digital microfluidics (DMF), facilitating independent manipulation of microliter samples, provides an ideal platform for immunoassay detection; however, suffering limited multiplexity. To address the need, herein we described a digital microfluidics (DMF) platform that realizes spatial barcoding on the Teflon-coated indium tin oxide (ITO) glass side to fulfill highly multiplexed immunoassay (10+) with low-volume samples (∼4 μL) in parallel, representing the highest multiplexing recorded to date for DMF-actuated immunoassay. Planar-based spatial immobilization of multiple capture antibodies was realized on a Teflon-coated ITO glass side, which was then used as the top plate of the DMF device. Droplets containing analytes , secondary antibodies, and fluorescent signaling reporters with low volume, which were electrically manipulated by our DMF control system, were shuttled sequentially along the working electrodes to complete the immuno-reaction. Evaluation of platform performance with recombinant proteins showed excellent sensitivity and reproducibility. To test the feasibility of our platform in analyzing multiplex biomarkers of the immune response, we used lipopolysaccharide-stimulated macrophages as a model system for protein secretion dynamics studies. As a result, temporal profiling of pro-inflammatory cytokine secretion dynamics was obtained. The spatial barcoding strategy presented here is easy-to-operate to enable a more comprehensive evaluation of protein abundance from biological samples, paving the way for new opportunities to realize multiplexity-associated applications with the DMF platform.
研究领域:
微流控
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生物化学
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免疫学
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分析化学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2019
·
IF 5.399
Yinyin Liao,Xiumin Fu,Haiyun Zhou,Wei Rao,Lanting Zeng,Ziyin Yang
Although specialized metabolite distributions in different tea ( Camellia sinensis ) tissues has been studied extensively, little is known about their within-tissue distribution owing to the lack of nondestructive methodology. In this study, desorption electrospray ionization imaging mass spectrometry was used to investigate the within-tissue spatial distributions of specialized metabolites in tea. To overcome the negative effects of the large amount of wax on tea leaves, several sample preparation methods were compared, with a Teflon-imprint method established for tea leaves. Polyphenols are characteristic metabolites in tea leaves. Epicatechin gallate/catechin gallate, epigallocatechin gallate/gallocatechin gallate, and gallic acid were evenly distributed on both sides of the leaves, while epicatechin/catechin, epigallocatechin/gallocatechin, and assamicain A were distributed near the leaf vein. L -Theanine was mainly accumulated in tea roots. L -Theanine and valinol were distributed around the outer root cross-section. The results will advance our understanding of the precise localizations and in-vivo biosyntheses of specialized metabolites in tea.
研究领域:
植物科学
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分析化学
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代谢组学
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产品关联
DOI
PubMed
高影响因子
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