| 1. |
- Chen, Zhiliang, et al.
(författare)
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Synergistic Catalysis by “Polymeric Microzymes and Inorganic Nanozymes” : The 1+1>2 Effect for Intramolecular Cyclization of Peptides
- 2017
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Ingår i: Frontiers in Chemistry. - : Frontiers Media S.A.. - 2296-2646. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we developed an efficient “molecularly imprinted polymer microzymes and inorganic magnetic nanozymes” synergistic catalysis strategy for the formation of disulfide bonds in peptides. The polymeric microzymes showed excellent selectivity toward the template peptide as well as the main reactant (linear peptide), and the Fe3O4 magnetic nanoparticle (MNP) nanozymes inhibited the intermolecular reaction during the formation of disulfide bonds in peptides. As a result, the integration of the two different artificial enzymes in one process facilitates the intramolecular cyclization in high product yields (59.3%) with excellent selectivity. Mechanism study indicates the synergistic effect was occurred by using a “reversed solid phase synthesis” strategy with an enhanced shift of reaction balance to product generation. We believe the synergistic catalysis by “polymeric microzymes and inorganic nanozymes” presented in the present work may open new opportunities in creation of multifunctional enzyme mimics for sensing, imaging, and drug delivery.
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| 2. |
- Gong, Haiyue, et al.
(författare)
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Synthesis of Bacteria Imprinted Polymers by Pickering Emulsion Polymerization
- 2021
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Ingår i: Methods in Molecular Biology. - New York, NY : Springer US. - 1064-3745 .- 1940-6029. ; 2359, s. 43-51
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Bokkapitel (refereegranskat)abstract
- Molecularly imprinted polymers have been studied for a long time and have found useful applications in many fields. In most cases, small organic molecules are used as templates to synthesize imprinted polymers. In contrast to low molecular weight targets, large biological molecules and cells are more challenging to use as templates to synthesize cell-recognizing materials. This chapter presents an interfacial imprinting method to synthesize bacteria-recognizing polymer beads using Pickering emulsion polymerization. The tendency of bacteria to reside between two immiscible liquids is utilized to create surface-imprinted binding sites on cross-linked polymer microspheres.
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| 3. |
- Huang, Chuixiu, et al.
(författare)
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Breath Figure Patterns Made Easy
- 2014
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 6:8, s. 5971-5976
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a simple breath figure method was proposed to directly fabricate large-area and ordered honeycomb structures on commercial PMMA substrates or PS Petri dishes without the use of an external polymer solution. The obtained honeycomb structure is indeed part of the substrate, providing the honeycomb layer with enough mechanical stability. The breath figure method in this work for the synthesis of honeycomb structure is extremely simple with scale-up capability to large-area production, which offers new insights into surface engineering with great potential in commercial technologies. For example, using the honeycomb-patterned Petri dishes prepared via this method, cells can be easily separated into divided aggregation, which favors understanding of naturally occurring networks in higher organisms and cell cell and cell matrix interactions, and the therapeutic control of genetic circuits.
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| 4. |
- Huang, Chuixiu, et al.
(författare)
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Janus molecularly imprinted polymer particles
- 2014
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X. ; 50:20, s. 2646-2649
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Tidskriftsartikel (refereegranskat)abstract
- By combining the specific molecular recognition capability of MIPs and the asymmetric structure of Janus particles, the Janus MIP particles which were synthesized via a wax-water Pickering emulsion showed attractive capabilities as self-propelled transporters for controlled drug delivery.
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| 5. |
- Huang, Chuixiu, et al.
(författare)
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Molecularly imprinted photocatalyst with a structural analogue of template and its application.
- 2013
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 1873-3336 .- 0304-3894. ; 248, s. 379-386
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Tidskriftsartikel (refereegranskat)abstract
- To realize selective mineralization of low-level chlorophenols (CPs) in the presence of high-level ordinary pollutants, molecularly imprinted polymers (MIPs) coated photocatalyst was prepared using substrate analog as template. The pseudo-template imprinted photocatalysts showed rapid decomposition ability toward a group of CPs. Based on the complete dechlorination and spectrophotometry, a new method was proposed to detect the total organochlorine on CPs in water samples. The method showed good linearity when the concentrations of the total organochlorine on CPs is in the range of 12.0-200.0μmolL(-1). The detection limit is 1μmolL(-1) for this method. When this method was applied to measure the total organochlorine of the CPs in both tap water and river water samples, an average recovery ranged from 96.3% to 105.1% was obtained with RSD values less than 5%. In this green and simple method, the common inorganic ions in water showed no interference for the detection. The determination of the total organochlorine on the CPs might be used for estimation of the toxicity and the persistence of the water samples.
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| 6. |
- Shen, Xiantao, et al.
(författare)
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Bacterial Imprinting at Pickering Emulsion Interfaces.
- 2014
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Ingår i: Angewandte Chemie (International edition). - : Wiley. - 1521-3773. ; 53:40, s. 10687-10690
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Tidskriftsartikel (refereegranskat)abstract
- The tendency of bacteria to assemble at oil-water interfaces can be utilized to create microbial recognition sites on the surface of polymer beads. In this work, two different groups of bacteria were first treated with acryloyl-functionalized chitosan and then used to stabilize an oil-in-water emulsion composed of cross-linking monomers that were dispersed in aqueous buffer. Polymerization of the oil phase followed by removal of the bacterial template resulted in well-defined polymer beads bearing bacterial imprints. Chemical passivation of chitosan and cell displacement assays indicate that the bacterial recognition on the polymer beads was dependent on the nature of the pre-polymer and the target bacteria. The functional materials for microbial recognition show great potential for constructing cell-cell communication networks, biosensors, and new platforms for testing antibiotic drugs.
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| 7. |
- Shen, Xiantao, et al.
(författare)
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Catalytic Formation of Disulfide Bonds in Peptides by Molecularly Imprinted Microgels at Oil/Water Interfaces
- 2016
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 8:44, s. 30484-30491
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Tidskriftsartikel (refereegranskat)abstract
- This work describes the preparation and investigation of molecularly imprinted polymer (MIP) microgels (MGs) stabilized Pickering emulsions (PE) for their ability to catalyze the formation of disulfide bonds in peptides at the O/W interface. The MIP MGs were synthesized via precipitation polymerization and a programmed initiator change strategy. The MIP MGs were characterized using DLS analysis, SEM measurement and optical microscopy analysis. The dry and wet MIP MGs showed a hydrodynamic diameter of 100 nm and 280 nm, respectively. Template rebinding experiment showed that the MIP MGs bound over two times more template (24 mg g-1) compared to the uptake displayed by a non-imprinted reference polymer (NIP) MG (10 mg g-1) at saturation. Using the MIP MGs as stabilizers, catalytic oxidation systems were prepared by emulsifying the oil phase and water phase in presence of different oxidizing agents. During the cyclization, the isolation of the thiol precursors and the oxidizing reagents non-selectively decreased the formation of the byproducts, while the imprinted cavities on the MIP MGs selectively promoted the intramolecular cyclization of peptides. When I2 was used as the oxidizing agent, the MIP-PE-I2 system showed a product yield of 50 %, corresponding to a nearly two-fold increase compared to the non-imprinted polymer NIP-PE-I2 system (26 %). We believe the interfacial catalysis system presented in this work may offer significant benefits in synthetic peptide chemistry by raising productivity while suppressing the formation of by-products.
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| 8. |
- 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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| 9. |
- Shen, Xiantao, et al.
(författare)
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Interfacial Molecular Imprinting in Nanoparticle-Stabilized Emulsions.
- 2011
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Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 44:14, s. 5631-5637
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Tidskriftsartikel (refereegranskat)abstract
- A new interfacial nano and molecular imprinting approach is developed to prepare spherical molecularly imprinted polymers with well-controlled hierarchical structures. This method is based on Pickering emulsion polymerization using template-modified colloidal particles. The interfacial imprinting is carried out in particle-stabilized oil-in-water emulsions, where the molecular template is presented on the surface of silica nanoparticles during the polymerization of the monomer phase. After polymerization, the template-modified silica nanoparticles are removed from the new spherical particles to leave tiny indentations decorated with molecularly imprinted sites. The imprinted microspheres prepared using the new interfacial nano and molecular imprinting have very interesting features: a well-controlled hierarchical structure composed of large pores decorated with easily accessible molecular binding sites, group selectivity toward a series of chemicals having a common structural moiety (epitopes), and a hydrophilic surface that enables the MIPs to be used under aqueous conditions.
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| 10. |
- Shen, Xiantao, et al.
(författare)
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Molecular imprinting for removing highly toxic organic pollutants
- 2012
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X. ; 48:6, s. 788-798
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Tidskriftsartikel (refereegranskat)abstract
- Molecular imprinting technology allows synthesis of polymers with specific recognition ability towards target pollutants, which show potential to selectively remove Highly Toxic Organic Pollutants (HTOPs) in the presence of common organic matrices that are thousands of times more abundant than the targets. This feature article summarizes the current development of molecular imprinting for removing HTOPs from polluted water, with a special emphasis on the application of molecularly imprinted polymers to improve the efficiency of photocatalytic and biological degradation of HTOPs in wastewater.
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| 11. |
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| 12. |
- Shen, Xiantao, et al.
(författare)
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Molecular imprinting of protein in Pickering emulsion.
- 2012
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X .- 1359-7345. ; 48:66, s. 8198-8200
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Tidskriftsartikel (refereegranskat)abstract
- A new strategy of molecular imprinting to prepare spherical hydrogels via water-in-oil Pickering emulsion polymerization was developed. The imprinted hydrogels exhibited fast adsorption kinetics and significant selectivity for the target protein.
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| 13. |
- 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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| 14. |
- 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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| 15. |
- Shen, Xiantao, et al.
(författare)
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Reflux precipitation polymerization : A new synthetic insight in molecular imprinting at high temperature
- 2016
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; :85, s. 81458-81461
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of uniform molecularly imprinted polymer (MIP) microspheres (MSs) using distillation precipitation polymerization (DPP) at high temperature has attracted great interest in the field of molecular imprinting. However, there are still some shortcomings in this method. In this work, to create uniform MIP MSs in a short time and to demonstrate the effects of high temperature on imprinting performance, a new precipitation polymerization method (reflux precipitation polymerization, RPP) was used for the first time to fabricate MIP MSs in this study. The SEM images of the polymeric MSs indicate the presence of template molecules could improve the particle morphology and size uniformity. The specific molecular recognition of the monodispersed MIP MSs was confirmed by fluorescence measurement and HPLC-UV analysis. The binding behavior of the MIP MSs was simulated using the heterogeneous Freundlich isotherm, which shows that the MIP MSs produced by the RPP possess compatible selectivity in comparison with those produced by traditional PP method. It is noted that, for the first time, we demonstrated that molecular imprinting at high temperature was only successful when electrostatic interactions played important roles in the imprinting process.
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| 16. |
- Xu, Changgang, et al.
(författare)
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Molecularly imprinted magnetic materials prepared from modular and clickable nanoparticles
- 2012
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 1364-5501 .- 0959-9428. ; 22:15, s. 7427-7433
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Tidskriftsartikel (refereegranskat)abstract
- We report a new strategy toward construction of functional composite materials for fast molecular separation. Molecularly imprinted nanoparticles containing surface-exposed alkyne groups were synthesized by one-pot precipitation polymerization. Magnetic Fe3O4 nanoparticles were first coated with a silica shell, and then modified with terminal azide groups. The two types of clickable nanoparticles were conjugated through a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction to give composite magnetic particles, which displayed high molecular recognition selectivity and could be easily separated using a simple magnet.
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| 17. |
- Xu, Changgang, et al.
(författare)
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Photoconjugation of Molecularly Imprinted Polymer with Magnetic Nanoparticles.
- 2013
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 5:11, s. 5208-5213
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Tidskriftsartikel (refereegranskat)abstract
- Because of their synthetic accessibility, molecularly imprinted polymer (MIP) nanoparticles are ideal building blocks for preparing multifunctional composites. In this work, we developed a general photocoupling chemistry to enable simple conjugation of MIP nanoparticles with inorganic magnetic nanoparticles. We first synthesized MIP nanoparticles using propranolol as a model template and perfluorophenyl azide-modified silica-coated magnetic nanoparticles. Using a simple photoactivation followed by facile purification with a magnet, we obtained magnetic composite particles that showed selective uptake of propranolol. We characterized the nanoparticles and composite materials using FT-IR, TEM, fluorescence spectroscopy, and radioligand binding analysis. Through the high molecular selectivity of the magnetic composite, we demonstrated the nondestructive feature and the high efficiency of the photocoupling chemistry. The versatile photoconjugation method developed in this work should also be very useful for combining organic MIPs with other inorganic nanoparticles to enable new chemical sensors and high efficiency photocatalysts.
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| 18. |
- Zhou, Tongchang, et al.
(författare)
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Molecularly Imprinted Polymer Beads Prepared by Pickering Emulsion Polymerization for Steroid Recognition
- 2014
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 1097-4628 .- 0021-8995. ; 131:1, s. 39606-39606
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Tidskriftsartikel (refereegranskat)abstract
- Pickering emulsion polymerization was used to synthesize molecularly imprinted polymer beads for the selective recognition of 17-beta-estradiol under aqueous conditions. Scanning electron microscopy analysis indicated that the imprinted polymer beads had a small diameter with a narrow size distribution (18.9 +/- 2.3 mu m). The reduction in particle size achieved in this study was attributed to the altered polarity of the stabilizing nanoparticles used in the Pickering emulsion. The imprinted polymer beads could be used directly in water and showed a high binding affinity for the template molecule, 17-beta-estradiol, and its structural analogs. These water-compatible polymer beads could be used as affinity adsorbents for the extraction and analysis of low-abundance steroid compounds in aqueous samples. (C) 2013 Wiley Periodicals, Inc.
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