| 1. |
- Hajizadeh, Solmaz, et al.
(författare)
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Cryogelation of molecularly imprinted nanoparticles: A macroporous structure as affinity chromatography column for removal of β-blockers from complex samples.
- 2013
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Ingår i: Journal of chromatography. A. - : Elsevier BV. - 1873-3778 .- 0021-9673. ; 1274, s. 6-12
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a new macroporous molecularly imprinted cryogel (MIP composite cryogel) was synthesized by glutaraldehyde cross-linking reaction of poly(vinyl alcohol) (PVA) particles and amino-modified molecularly imprinted core-shell nanoparticles. The MIP core-shell nanoparticles were prepared using propranolol as a template by one-pot precipitation polymerization with sequential monomer addition. The characteristics of the MIP composite cryogel were studied by scanning electron microscopy (SEM) and texture analyzer. The macroporous structure of the composite (with the pore size varying from a few micrometers to 100μm) enabled high mass transfer of particulate-containing fluids. In a solid phase extraction (SPE) process, the efficiency and selectivity of the MIP composite cryogel were investigated, where the cryogel was used as an affinity matrix to remove propranolol from aqueous solution as well as from complex plasma sample without prior protein precipitation. The MIP composite cryogel maintained high selectivity and stability and could be used repeatedly after regeneration.
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| 2. |
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| 3. |
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| 4. |
- Kamra, Tripta, et al.
(författare)
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Covalent immobilization of molecularly imprinted polymer nanoparticles on a gold surface using carbodiimide coupling for chemical sensing.
- 2016
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 461, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- One challenging task in building (bio)chemical sensors is the efficient and stable immobilization of receptor on a suitable transducer. Herein, we report a method for covalent immobilization of molecularly imprinted core-shell nanoparticles for construction of robust chemical sensors. The imprinted nanoparticles with a core-shell structure have selective molecular binding sites in the core and multiple amino groups in the shell. The model Au transducer surface is first functionalized with a self-assembled monolayer of 11-mercaptoundecanoic acid. The 11-mercaptoundecanoic acid is activated by treatment with carbodiimide/N-hydroxysuccinimide and then reacted with the core-shell nanoparticles to form amide bonds. We have characterized the process by studying the treated surfaces after each preparation step using atomic force microscopy, scanning electron microscopy, fluorescence microscopy, contact angle measurements and X-ray photoelectron spectroscopy. The microscopy results show the successful immobilization of the imprinted nanoparticles on the surface. The photoelectron spectroscopy results further confirm the success of each functionalization step. Further, the amino groups on the MIP surface were activated by electrostatically adsorbing negatively charged Au colloids. The functionalized surface was shown to be active for surface enhanced Raman scattering detection of propranolol. The particle immobilization and surface enhanced Raman scattering approach described here has a general applicability for constructing chemical sensors in different formats.
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| 5. |
- Kamra, Tripta, et al.
(författare)
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Covalent immobilization of molecularly imprinted polymer nanoparticles using an epoxy silane.
- 2015
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 445, s. 277-284
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Tidskriftsartikel (refereegranskat)abstract
- Molecularly imprinted polymers (MIPs) can be used as antibody mimics to develop robust chemical sensors. One challenging problem in using MIPs for sensor development is the lack of reliable conjugation chemistry that allows MIPs to be fixed on transducer surface. In this work, we study the use of epoxy silane to immobilize MIP nanoparticles on model transducer surfaces without impairing the function of the immobilized nanoparticles. The MIP nanoparticles with a core-shell structure have selective molecular binding sites in the core and multiple amino groups in the shell. The model transducer surface is functionalized with a self-assembled monolayer of epoxy silane, which reacts with the core-shell MIP particles to enable straightforward immobilization. The whole process is characterized by studying the treated surfaces after each preparation step using atomic force microscopy, scanning electron microscopy, fluorescence microscopy, contact angle measurements and X-ray photoelectron spectroscopy. The microscopy results show that the MIP particles are immobilized uniformly on surface. The photoelectron spectroscopy results further confirm the action of each functionalization step. The molecular selectivity of the MIP-functionalized surface is verified by radioligand binding analysis. The particle immobilization approach described here has a general applicability for constructing selective chemical sensors in different formats.
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| 6. |
- Kamra, Tripta, et al.
(författare)
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Photoconjugation of Molecularly Imprinted Polymer Nanoparticles for Surface-Enhanced Raman Detection of Propranolol
- 2015
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 7:49, s. 27479-27485
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Tidskriftsartikel (refereegranskat)abstract
- We report a simple and versatile method to covalently immobilize molecularly imprinted polymer (MIP) nanoparticles on a Raman active substrate (Klarite) using a disulfide-derivatized perfluorophenylazide (PFPA-disulfide). Gold-coated Klarite was functionalized with PFPA-disulfide via a gold sulfur bond. Upon light radiation, the available azido groups were converted to highly reactive singlet perfluorophenyl nitrene that undergoes a CH insertion reaction and form covalent bonds with the MIP nanoparticles. The resulting surfaces were characterized using scanning electron microscopy and surface enhanced Raman spectroscopy to study the morphology and template affinity of the surfaces, respectively. The Raman measurements clearly show a dose-responsive signal when propranolol binds to the MIP surface. Because the MIP particles were covalently attached to the Raman active substrate, the sensing surface was stable and could be reused after regeneration in acetic acid solution. The MIP-based Raman sensor was used successfully to detect propranolol in urine samples (7.7 X 10(-4) M). Our results show that the high selectivity of MLPs and the fingerprint Raman identification can be integrated into a compact sensing unit using high-efficiency photoconjugation. Thus, the method proposed is reliable, efficient and fast for fabricating label-free chemical sensors.
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| 7. |
- Shen, Xiantao, et al.
(författare)
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Imprinted polymer beads enabling direct and selective molecular separation in water
- 2012
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Ingår i: Soft Matter. - : Royal Society of Chemistry (RSC). - 1744-6848 .- 1744-683X. ; 8:27, s. 7169-7176
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we describe the synthesis of water-compatible Molecularly Imprinted Polymer (MIP) microspheres by nanoparticle-stabilized emulsion (Pickering emulsion) polymerization. During the polymerization, the amount of the porogen used not only affected the stability of the Pickering emulsion but also the specific molecular recognition of the obtained MIP microspheres. Under optimized conditions, the MIP microspheres synthesized had a porous and hydrophilic surface. Scanning electron microscopy and fluorescent labeling experiments indicated that the MIP microspheres had particle sizes of 165 +/- 38 mu m. Selective molecular recognition with the MIP microspheres was studied through equilibrium binding analysis and liquid chromatography experiments under pure aqueous conditions. Using the new MIP microspheres as solid phase extraction (SPE) absorbents, low concentration organic pollutants (beta-blockers) were effectively enriched from tap water and easily detected using HPLC-MS analysis.
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| 8. |
- Shen, Xiantao, et al.
(författare)
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Molecular recognition with colloidosomes enabled by imprinted polymer nanoparticles and fluorogenic boronic acid
- 2013
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Ingår i: Journal of Materials Chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-7518 .- 2050-750X. ; 1:36, s. 4612-4618
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Tidskriftsartikel (refereegranskat)abstract
- Multifunctional colloidosomes are prepared from molecularly imprinted polymer nanoparticles and fluorogenic boronic acid using a Cu(I)-catalyzed click reaction. The molecular selectivity of the colloidosomes was investigated by radioligand binding analysis, which indicated that the inter-particle click reaction did not affect the molecular specificity of the MIP nanoparticles on the colloidosomes for the model template, propranolol. Besides specific molecular recognition of the MIP nanoparticles, the colloidosomes also displayed dose-dependent fluorescence response to fructose at physiological pH. Moreover, the immobilized boronic acid in the core could effectively bind isoproterenol, a template analogue containing a catecholamine moiety. The depletion of isoproterenol from solution allowed the MIP nanoparticles on the colloidosomes to bind propranolol more efficiently. The pre-designed molecular selectivity and fluorescence response of the colloidosomes are interesting for potential applications in controlled delivery, chemical sensing and bioseparation.
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| 9. |
- Shen, Xiantao, et al.
(författare)
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Molecularly Imprinted Polymers for Clean Water: Analysis and Purification
- 2013
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 52:39, s. 13890-13899
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Tidskriftsartikel (refereegranskat)abstract
- Because of their predetermined selectivity, molecularly imprinted polymers (MIPs) have been extensively investigated to offer efficient separation of organic pollutants for water analysis and purification. In this review, we first describe the current development of water compatible MIPs, and the physical encapsulation and chemical immobilization of MIP particles for practical applications related to water analysis and purification. We summarize the challenges in understanding the mechanisms in molecular imprinting, with a special emphasis on the use of nuclear magnetic resonance (NMR), dynamic light scattering (DLS), and synchronous fluorescence spectroscopy to gain theoretical insights into the molecular imprinting process. The highlighted synthetic methods and the mechanistic investigations discussed in this review should facilitate the identification of the most crucial factors affecting the applications of MIPs for clean water.
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| 10. |
- Shi, Liyang, et al.
(författare)
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Biocompatible Injectable Magnetic Hydrogel Formed by Dynamic Coordination Network
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:49, s. 46233-46240
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic hydrogel that can respond to a magnetic stimulus is a promising biomaterial for tissue regeneration and cancer treatment. In this study, a novel magnetic hydrogel is formed by simply mixing bisphosphonate (BP)-modified hyaluronic acid (i.e., HA-BP) polymeric solution and iron oxide (Fe3O4) nanoparticle dispersion, in which the hydrogel networks are cross linked by BP groups and iron atoms on the surface of particle. The iron BP coordination chemistry affords a dynamic network, characterized by self-healing, shear-thinning, and smoothly injectable properties. Moreover, the HA-BP-Fe3O4 magnetic hydrogel demonstrates heat-generation characterization under an alternating magnetic field. The animal experiments confirm the biocompatibilities of HA BP center dot Fe3O4 hydrogel, which presents the hydrogels potential for tissue regeneration and anticancer treatment applications.
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