| 1. |
- Zhang, Yan, et al.
(författare)
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Classification of Lipases Using Pattern Recognition through Transformation of Dynamic Hemithioacetal Systems
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A complex dynamic hemithioacetal system was generated for the evaluation of lipase reactivities. In combination with pattern recognition methodology, twelve different lipases were successfully classified into three distinct groups following their reaction selectivities and reactivities. A probe lipase was further categorized using the training matrix with predicted reactivity.
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| 2. |
- Zhang, Yan, et al.
(författare)
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Enzyme classification using complex dynamic hemithioacetal systems
- 2016
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 52:28, s. 5053-5056
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Tidskriftsartikel (refereegranskat)abstract
- A complex dynamic hemithioacetal system was generated for the evaluation of lipase reactivities in organic media. In combination with pattern recognition methodology, twelve different lipases were successfully classified into four distinct groups following their reaction selectivities and reactivities. A probe lipase was further categorized using the training matrix with predicted reactivity.
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| 3. |
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| 4. |
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| 5. |
- Al-Bataineh, Sameer A., et al.
(författare)
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Covalent Immobilization of Antibacterial Furanones via Photochemical Activation of Perfluorophenylazide
- 2009
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 25:13, s. 7432-7437
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Tidskriftsartikel (refereegranskat)abstract
- N-(3-Trimethoxysilylpropyl)-4-azido-2,3,5,6-tetrafluorobenzamide (PFPA-silane) was used as a photoactive crosslinker to immobilize antibacterial furanone molecules on silicon oxide surfaces. This immobilization strategy is useful, especially for substrates and molecules that lack reactive functional groups. To this end, cleaned wafers were initially incubated in solutions of different concentrations of PFPA-silane to form a monolayer presenting azido groups on the surface. The functionalized surfaces were then treated with a furanone solution followed by illumination with UV light and extensive rinsing with ethanol to remove noncovalently adhered molecules, In the presented study, we demonstrate the ability to control the surface density of the immobilized furanone molecules by adjusting the concentration of PFPA-silane solution used for surface functionalization using complementary surface analytical techniques. The fluorine in PFPA-silane and the bromine in furanone molecules were convenient markers for the XPS study. The ellipsometric layer thickness of the immobilized furanone molecules on the surface decreased with decreasing PFPA-silane concentration, which correlated with a decline of water contact angle as a sign of film collapse. The intensity of characteristic azide vibration in the MTR IR spectra was monitored as a function of PFPA-silane concentration, and the peak disappeared completely after furanone application followed by UV irradiation. As a complementary technique to XPS, TOF-SIMS provided valuable information on the chemical and molecular structure of the modified surfaces and spatial distribution of the immobilized furanone molecules. Finally, this report presents a convenient, reproducible, and robust strategy to design antibacterial coating based on furanone compounds for applications in human health care.
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| 6. |
- Chada, Sailaja, et al.
(författare)
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Self-assembled nanostructures from homopolymer induced by UV and solvent exposure
- 2008
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-683X .- 1744-6848. ; 4:11, s. 2164-2167
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Tidskriftsartikel (refereegranskat)abstract
- A simple method for creating self-assembled nanostructures using a single polymer system is reported. When spin-coated polystyrene thin films were irradiated with UV light and treated with toluene, unique nanostructures were observed, evolving from star-shaped networks to arrays of concentric circles. The nanostructure formation is a result of differential responses of crosslinked and oxidized products to the solvent by a combined effect of phase separation and solvent swelling. The nanostructures were observed for polymers of different molecular weights, films of different thicknesses, and on various substrates.
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| 7. |
- Chaudhary, Shilpi, et al.
(författare)
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Controlled short-linkage assembly of functional nano-objects
- 2014
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Ingår i: Applied Surface Science. - : Elsevier BV. - 1873-5584 .- 0169-4332. ; 300, s. 22-28
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report a method that allows the deterministic, photo-controlled covalent assembly of nanoparticles directly on surface. As a model system, we study the conjugation of molecularly imprinted polymer (MIP) nanoparticles on a glass surface and confirm that the immobilized nanoparticles maintain their molecular recognition functionality. The glass slide was first modified with perfluorophenylazide and then used to bind MIP nanoparticles under UV irradiation. After each step the surface was analyzed by water contact angle measurement, fluorescence microscopy, scanning electron microscopy, and/or synchrotron-based X-ray photoelectron spectroscopy. The MIP nanoparticles immobilized on the glass surface remained stable and maintained specific binding for the template molecule, propranolol. The method developed in this work allows MIP nanoparticles to be directly coupled to a flat surface, offering a straightforward means to construct robust chemical sensors. Using the reported photo conjugation method, it is possible to generate patterned assembly of nanoparticles using a photomask. Since perfluorophenylazide-based photochemistry works with all kinds of organic material, the method developed in this work is expected to enable immobilization of not only MIPs but also other kinds of organic and inorganic-organic core-shell particles for various applications involving photon or electron transfer. (C) 2014 The Authors. Published by Elsevier B.V. All rights reserved.
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| 8. |
- Chen, Xuan, et al.
(författare)
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Glyconanomaterials : Emerging applications in biomedical research
- 2014
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Ingår i: Nano Reseach. - : Springer Science and Business Media LLC. - 1998-0124 .- 1998-0000. ; 7:10, s. 1381-1403
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Forskningsöversikt (refereegranskat)abstract
- Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct optical, magnetic, and electronic properties has witnessed a rapid adoption of these materials for biomedical research and applications. Nanomaterials of various shapes and sizes having large specific surface areas can be used as multivalent scaffolds to present carbohydrate ligands. The resulting glyconanomaterials effectively amplify the glycan-mediated interactions, making it possible to use these materials for sensing, imaging, diagnosis, and therapy. In this review, we summarize the synthetic strategies for the preparation of various glyconanomaterials. Examples are given where these glyconanomaterials have been used in sensing and differentiation of proteins and cells, as well as in imaging glycan-medicated cellular responses.
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| 9. |
- Chen, Y. C., et al.
(författare)
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Evaluation of molecularly imprinted polyurethane as an optical waveguide for PAH sensing
- 2004
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Ingår i: NANOSENSING. - : SPIE. ; , s. 513-520
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Konferensbidrag (refereegranskat)abstract
- We developed a numerical model for the fluorescence output efficiency of a molecularly imprinted polymer (MIP) waveguide sensing system. A polyurethane waveguide imprinted with a polycyclic aromatic hydrocarbon (PAH) molecule was fabricated using micromolding in capillaries. The coupling of light into a 5 mm long MIP segment was verified by comparing the output transmission signals of a deuterium lamp from the MIP waveguide collected by, an optical fiber with the background lamp signals collected by the same optical fiber. It was found that polyurethane MIP was an effective waveguide but absorbed much shorter wavelengths, especially ill the UV region. thereby the transmission of light appeared orange/red in color. The high background absorption of polyurethane in the spectrometric regions of interest was found to be a critical problem for sensor sensitivity. Our numerical model shows that the fluorescence output is only 2 X 10(-6) of the input excitation for 25 mM anthracene for a 5mm polyurethane waveguide. A 10 fold decrease of background absorption will increase the fluorescence output 250 times.
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| 10. |
- Chen, Y. C., et al.
(författare)
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Fluorescence anisotropy studies of molecularly imprinted polymers
- 2006
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Ingår i: Luminescence (Chichester, England Print). - : Wiley. - 1522-7235 .- 1522-7243. ; 21:1, s. 7-14
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Tidskriftsartikel (refereegranskat)abstract
- A molecularly imprinted polymer (MIP) is a biomimetic material that can be used as a biochemical sensing element. We studied the steady-state and time-resolved fluorescence and fluorescence anisotropy of anthracene-imprinted polyurethane. We compared MIPs with imprinted analytes present, MIPs with the imprinted analytes extracted, MIPs with rebound analytes, non-imprinted control polymers (non-MIPs) and non-MIPs bound with analytes to understand MIP’s binding behaviour. MIPs and non-MIPs had similar steady-state fluorescence anisotropy in the range 0.11-0.24. Anthracene rebound in MIPs and non-MIPs had a fluorescence lifetime of tau = 0.64 ns and a rotational correlation time of 0, = 1.2-1.5 ns, both of which were shorter than that of MIPs with imprinted analytes present (tau = 2.03 ns and phi(F) = 2.7 ns). The steady-state anisotropy of polymer solutions increased exponentially with polymerization time and might be used to characterize the polymerization extent in situ.
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