Surface functionalized magnetic iron oxide nanoparticles (NPs) are a kind of novel functional materials, which have been widely used in the biotechnology and catalysis. This review focuses on the recent development and various strategies in preparation, structure, and magnetic properties of naked and surface functionalized iron oxide NPs and their corresponding application briefly. In order to implement the practical application, the particles must have combined properties of high magnetic saturation, stability, biocompatibility, and interactive functions at the surface. Moreover, the surface of iron oxide NPs could be modified by organic materials or inorganic materials, such as polymers, biomolecules, silica, metals, etc. The problems and major challenges, along with the directions for the synthesis and surface functionalization of iron oxide NPs, are considered. Finally, some future trends and prospective in these research areas are also discussed.

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Magnetic Iron Oxide Nanoparticles: Synthesis and Surface Functionalization Strategies

Biocompatibility, Pharmaceutical and Biomedical Applications L. Harivardhan Reddy,†,‡ Jose ́ L. Arias, Julien Nicolas,† and Patrick Couvreur*,† †Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, Universite ́ Paris-Sud XI, UMR CNRS 8612, Faculte ́ de Pharmacie, IFR 141, 5 rue Jean-Baptiste Cleḿent, F-92296 Chat̂enay-Malabry, France Departamento de Farmacia y Tecnología Farmaceútica, Facultad de Farmacia, Campus Universitario de Cartuja s/n, Universidad de Granada, 18071 Granada, Spain ‡Pharmaceutical Sciences Department, Sanofi, 13 Quai Jules Guesdes, F-94403 Vitry-sur-Seine, France

Magnetic nanoparticles: design and characterization, toxicity and biocompatibility, pharmaceutical and biomedical applications.

Silicon is regarded as one of the most promising anode materials for next generation lithium-ion batteries. For use in practical applications, a Si electrode must have high capacity, long cycle life, high efficiency, and the fabrication must be industrially scalable. Here, we design and fabricate a yolk-shell structure to meet all these needs. The fabrication is carried out without special equipment and mostly at room temperature. Commercially available Si nanoparticles are completely sealed inside conformal, thin, self-supporting carbon shells, with rationally designed void space in between the particles and the shell. The well-defined void space allows the Si particles to expand freely without breaking the outer carbon shell, therefore stabilizing the solid-electrolyte interphase on the shell surface. High capacity (∼2800 mAh/g at C/10), long cycle life (1000 cycles with 74% capacity retention), and high Coulombic efficiency (99.84%) have been realized in this yolk-shell structured Si electrode.

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A yolk-shell design for stabilized and scalable li-ion battery alloy anodes.

http://pharmaquest.weebly.com/uploads/9/9/4/2/9942916/superparamagnetic_iron_oxide_nanoparticles_spions.pdf

Superparamagnetic iron oxide nanoparticles (SPIONs): Development, surface modification and applications in chemotherapy

Energy shortage, environmental crisis, and developing customer demands have driven people to find facile, low-cost, environmentally friendly, and nontoxic routes to produce novel functional materials that can be commercialized in the near future. Amongst various techniques, the hydrothermal carbonization (HTC) process of biomass (either of isolated carbohydrates or crude plants) is a promising candidate for the synthesis of novel carbon-based materials with a wide variety of potential applications. In this Review, we will discuss various synthetic routes towards such novel carbon-based materials or composites via the HTC process of biomass. Furthermore, factors that influence the carbonization process will be analyzed and the special chemical/physical properties of the final products will be discussed. Despite the lack of a clear mechanism, these novel carbonaceous materials have already shown promising applications in many fields such as carbon fixation, water purification, fuel cell catalysis, energy storage, CO(2) sequestration, bioimaging, drug delivery, and gas sensors. Some of the most promising examples will also be discussed here, demonstrating that the HTC process can rationally design a rich family of carbonaceous and hybrid functional carbon materials with important applications in a sustainable fashion.

Engineering Carbon Materials from the Hydrothermal Carbonization Process of Biomass

Superparamagnetic microspheres with an Fe3O4@SiO2 core and a perpendicularly aligned mesoporous SiO2 shell were synthesized through a surfactant-templating sol−gel approach. The microspheres possess high magnetization (53.3 emu/g), high surface area (365 m2/g), large pore volume (0.29 cm3/g), and uniform mesopore (2.3 nm). By using the unique core−shell microspheres with accessible large pores and excellent magnetic property, a fast removal of microcystins with high efficiency (>95%) can be achieved.

Superparamagnetic high-magnetization microspheres with an Fe3O4@SiO2 core and perpendicularly aligned mesoporous SiO2 shell for removal of microcystins.

Colloidal particles with controlled structures, morphologies, and functionalities have attracted much attention because of their potential application in column-packing substrates, photonic crystals, drug delivery, chemical sensors, catalysis carriers, and separation of biomacromolecules. In particular, colloidal magnetic microspheres have long been of great interest as hybrid materials, because of their perfect combination of easily functionalizable surfaces and magnetic responsiveness. This combination endows them with great potential for use in miniature devices, where easy manipulation, separation, and site-specific targeting via a magnetic field are desired. A variety of approaches have been explored to synthesize magnetic microspheres, including encapsulation ofmagnetite particles by organic polymers, such as polystyrene, and coating magnetic particles with inorganic silica via sol-gel processes. Possible applications ofmagneticmicrospheres have also been explored infields such as cell sorting, separation of biomolecules, and so on. Recently, great efforts have been focused on enhancing the performance of magnetic microspheres. These include efforts to improve their magnetic-field responsiveness, so as to achieve effective manipulation, and efforts to introduce additional functionalities, in order to tailor their physicochemical properties (e.g., high surface area and functional groups) to achieve affinity binding or specific conjugation. In this regard, we have synthesized submicrometer-sized magnetic microspheres by coating magnetite particles with silica through a modified sol-gel approach; these microspheres proved to be useful in the enrichment of low-abundance peptides. Based on the heterointerparticle coalescence strategy, Park et al. prepared magnetic iron-oxide/Au microspheres, and used them in bioassays. Kim et al. reported on the production of magnetic fluorescent porous microspheres by simultaneously encapsulating magnetite nanoparticles and CdSe/ZnS quantum dots with mesoporous silica. Shi and coworkers synthesized magnetic microspheres with disordered mesoporous silica shells. More recently, using a sol-gel synthesis that involved a surfactant, high-magnetization, magnetic, mesoporous, silica microspheres with perpendicularly aligned mesoporous silica shells were reported. These microspheres have been used for the efficient removal of microcystins in water. Microporous zeolites are important inorganic materials with open-framework aluminosilicate structures, and have been extensively used in industrial processes such as gas separation and petrochemical-based catalysis. Zeolite particles, because of their low-toxicity, good capability, functional groups for grafting or attachment, and high dispersability, have been demonstrated to be good biomaterials in various applications, such as in the immobilization of trypsin for microreactors in microfluidic systems and for the highly efficient enrichment of low-abundance peptides in protein identification. However, unlike ordered mesoporous silicates (whose synthesis involves self-assembly of a surfactant-templating sol-gel process at low temperatures, e.g., room temperature), zeolites are usually synthesized using high-temperature hydrothermal processes. As a result, the synthesis of core/shell zeolite microspheres remains a great challenge, because of the difficulty in controlling the growth of zeolite crystals on the magnetite particles. In this communication, we report a novel approach to synthesizing core/shell-structured magnetic zeolite microspheres (MZMs) with uniform variable diameters (from ca. 600 nm to 1mm). The approach combines sol-gel synthesis of a zeolite seed coating and vapor-phase transport (VPT) for growing the zeolite crystal shells. The colloidal MZMs, which consist of a magnetite core (ca. 400 nm in diameter) and a zeolite shell (ca. 180 nm thick), have a well-defined core/shell structure and a high magnetization of 48.5 emug 1 (emu: electromagnetic units), and exhibit good dispersability in water. Moreover, these microspheres show a strong affinity to trypsin with a high adsorption capacity (62mgmg ). Using trypsin-immobilized MZMs (T-MZMs), highly efficient protein digestion is achieved, with the assistance of microwave irradiation, in only 15 s, which is much faster than digestion in solution. Moreover, the T-MZMs can be conveniently recovered by simple magnetic separation, and reused at least seven times without any visible reduction in digestion efficiency. The synthesis procedure for the core/shell MZMs consists of three main steps, as shown in Scheme 1. First, Fe3O4/SiO2 microspheres are synthesized by coating Fe3O4 particles with a layer of silica via a sol-gel process. The silica layer prevents erosion during the hydrothermal process, and functions as the silica source for the growth of the zeolite crystals. Second, in order to deposit the negatively charged zeolitic seeds on the silica surfaces of the microspheres, a cationic polyelectrolyte, poly (diallydimethylammonium chloride) (PDDA), was used tomodify the surfaces of the Fe3O4/SiO2 microspheres; the zeolite seed nanoparticles (silicalite-1) were then adsorbed on the surfaces by Coulomb interaction. Third, the microspheres were subject to

Synthesis of Core/Shell Colloidal Magnetic Zeolite Microspheres for the Immobilization of Trypsin

Due to the dynamic nature and low stoichiometry of protein phosphorylation, enrichment of phosphorylated peptides from proteolytic mixtures is often necessary prior to their characterization by mass spectrometry. Immobilized metal affinity chromatography (IMAC) is a popular way to enrich phosphopeptides; however, conventional IMAC lacks enough specificity for efficient phosphoproteome analysis. In this study, novel Fe3O4@TiO2 microspheres with well-defined core−shell structure were prepared and developed for highly specific purification of phosphopeptides from complex peptide mixtures. The enrichment conditions were optimized using tryptic digests of β-casein, and the high specificity of the Fe3O4@TiO2 core−shell microspheres was demonstrated by effectively enriching phosphopeptides from the digest mixture of α-casein and β-casein, as well as a five-protein mixture containing nonphosphoproteins (bovine serum albumin (BSA), myoglobin, cytochrome c) and phosphoproteins (ovalbumin and β-casein). The Fe3O4@Ti...

Novel Fe3O4@TiO2 core-shell microspheres for selective enrichment of phosphopeptides in phosphoproteome analysis.

Novel approach for the synthesis of Fe3O4@TiO2 core–shell microspheres and their application to the highly specific capture of phosphopeptides for MALDI-TOF MS analysis

A fast and efficient proteolysis approach of microwave-assisted protein digestion was developed by using trypsin-immobilized magnetic silica (MS) microspheres. In the work, immobilization of the enzyme onto MS microspheres was very simple and only through a one-step reaction with 3-glycidoxypropyltrimethoxysilane (GLYMO) which provides the epoxy group as a reactive spacer. Considering that the magnetic particles are excellent microwave absorbers, we developed a novel microwave-assisted digestion method based on the easily prepared trypsin-immobilized MS microspheres. This novel digestion method combined the advantages of immobilized trypsin and the rapid-fashion of microwave-assisted digestion, which resulted in high digestion efficiency. BSA and myoglobin were used as model proteins to optimize the conditions of this method. Peptide fragments produced in 15 s could be confidently identified by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. Equivalent...

Dawei Qi

Papers

Superparamagnetic high-magnetization microspheres with an Fe3O4@SiO2 core and perpendicularly aligned mesoporous SiO2 shell for removal of microcystins.

Synthesis of Core/Shell Colloidal Magnetic Zeolite Microspheres for the Immobilization of Trypsin

Novel Fe3O4@TiO2 core-shell microspheres for selective enrichment of phosphopeptides in phosphoproteome analysis.

Novel approach for the synthesis of Fe3O4@TiO2 core–shell microspheres and their application to the highly specific capture of phosphopeptides for MALDI-TOF MS analysis

Fast and efficient proteolysis by microwave-assisted protein digestion using trypsin-immobilized magnetic silica microspheres.