Yunhua Wang

A Facile One‐Step Solvothermal Synthesis of SnO2/Graphene Nanocomposite and Its Application as an Anode Material for Lithium‐Ion Batteries

Spare capacity: A SnO/graphene nanocomposite is fabricated by a novel solvothermal method (see picture). The nanocomposite exhibits a reversible lithium storage capacity of 838 mAhg in the first cycle and improved cyclability as an anode material for lithium-ion batteries.

Ultrasmall, well-dispersed, hollow siliceous spheres with enhanced endocytosis properties.

The synthesis of ultrasmall, well-dispersed, hollow siliceous spheres (HSSs) by using a block copolymer as the template and tetraethoxysilane as a silica source under acidic conditions is reported. After removing the surfactant core of as-synthesized, spherical, silica-coated block-copolymer micelles, HSSs with a uniform particle size of 24.7 nm, a cavity diameter of 11.7 nm, and a wall thickness of 6.5 nm are obtained. It is shown that by surface functionalization of HSSs with methyl groups during synthesis, HSSs can be further dispersed in solvents such as water or ethanol to form a stable sol. Moreover, the hollow cavities are accessible for further loading of functional components. In addition, it is demonstrated that HSSs possess superior endocytosis properties for HeLa cells compared to those of conventional mesoporous silica nanoparticles. A feasible and designable strategy for synthesizing novel well-dispersed hollow structures with ultrasmall diameters instead of conventional ordered mesostructures is provided. It is expected that HSSs may find broad applications in bionanotechnology, such as drug carriers, cell imaging, and targeted therapy.

TiO2‐Modified Macroporous Silica Foams for Advanced Enrichment of Multi‐Phosphorylated Peptides

Enriching peptides: Novel TiO(2)-modified macroporous materials (Ti-MOSF, see figure) have been synthesized with high surface area, large pore volume, and functional surfaces that are rich in coordinatively unsaturated Ti(IV) species, which can be applied in the specific extraction of phosphopeptides and which show a preferential capture of multi-phosphorylated peptides with low detection limits and high selectivity.

Macroporous Materials as Novel Catalysts for Efficient and Controllable Proteolysis

A novel nanopore based digestion strategy has been developed by directly adding a macroporous material as catalyst to the conventional in-solution reaction system. Without increasing the enzyme or protein concentrations, this simple digestion approach exhibits high proteolysis efficiency and selectivity due to the in situ fast adsorption of both enzymes and proteins from bulk solution into the macropores of the catalysts, where the target substrates and enzymes are greatly concentrated and confined in the nanospace to realize a quick digestion. Based on the electrostatic interaction matching between the biomolecules and catalysts, selective extraction and digestion of proteins with different isoelectric points can be achieved by adjusting the surface charge of the catalysts. This nanoporous reaction system has been successfully applied to the analysis of a complex biological sample, where 293 proteins are identified, while only 100 proteins are obtained by the standard overnight in-solution digestion. The present nanospace confined digestion strategy will lead to promising advances not only in proteomics but also in other applications where enzymatic reactions are involved.

Functionalized Periodic Mesoporous Organosilicas for Enhanced and Selective Peptide Enrichment

The analysis of peptides by the mass spectrometry (MS) technique is important in modern life science. The enrichment of peptides can increase the detection efficiency and is sometimes indispensable for collecting the information on proteins with low-abundance. Herein, we first report that functionalized periodic mesoporous organosilica (PMO) materials have a superior peptide enrichment property. It is demonstrated that the PMO materials with an organo-bridged (-CH(2)-) hybrid wall composition display a highly enhanced peptide enrichment ability compared to the pure silica material (SBA-15) with similar mesostructured parameters and morphology. More importantly, by surface modification of PMO with amino groups (denoted NH(2)-PMO), PMO and NH(2)-PMO with opposite charged surfaces (-25.2 and +39.0 mV, respectively) show selective affinities for positively and negatively charged peptides, respectively. By directly adding PMO, NH(2)-PMO as well as pure silica materials to the peptides solution with a low concentration (1-2 fmol/microL), 36 and 28 peptides can be detected from the BSA digestion in the presence of PMO and NH(2)-PMO, respectively, while only 6 and 4 are monitored in the case of SBA-15 enrichment and from solution without enrichment, respectively. Moreover, 69.4% (25 of 36) of enriched peptides by PMO have pI > or = 6 and 80% (21 of 28) of enriched peptides by NH(2)-PMO possess pI < or = 6. Combining the results from the NH(2)-PMO and PMO enrichment together, 51 peptides can be identified with a MOWSE score of 333. It is also noted that similar conclusions can also be obtained from the peptides solution originated from other proteins. This might be an important contribution to the understanding of the interaction between peptides and porous hosts, and the proposed method is promising for the development of both material science and biotechnology.

Enrichment and detection of peptides from biological systems using designed periodic mesoporous organosilica microspheres

Periodic mesoporous organosilica microspheres (PMOMs) are designed with integrated structural features, including a cubic mesostructure, hydrophobic wall composition, a uniform pore size of ≈3 nm, and a spherical morphology in micrometers, all advantageous for size-selective and highly efficient enrichment of peptides from mixtures. Consequently, PMOMs can be used to capture peptides in a range of complex biological systems.

Small Mesoporous Silica Nanoparticles as Carriers for Enhanced Photodynamic Therapy

Small mesoporous silica nanoparticles (MSNs; ca. 37 nm in diameter) have a high loading capacity for a hydrophobic photosensitizer, SiPcCl(2) (82.6% in weight), and excellent endocytosis properties. As a result, the amount of SiPcCl(2) being delivered to cancer cells is increased by approximately two orders of magnitude compared to pure SiPcCl(2) at the same dosage, and the photodynamic therapy (PDT) efficiency is enhanced by over fourfold. Our method can be widely used to increase the dosage of hydrophobic anti-cancer drugs in cancer cells and therefore increase the cytotoxicity of the drugs.

Periodic Mesoporous Organosilicas with Helical and Concentric Circular Pore Architectures

This study systematically investigates periodic mesoporous organosilicas (PMOs) with controlled helical and concentric circular (CC) pore architectures prepared through a basic-catalyzed sol-gel process by using an achiral cationic surfactant trimethyloctadecylammonium bromide (C(18)TAB) as a structure-directing agent, perfluorooctanoic acid (PFOA) as an additive, and 1,2-bis(triethoxysilyl)ethane (BTEE) as a hybrid silica precursor. By increasing the weight ratio of PFOA/C(18)TAB, a pore architecture transition of PMO materials from hexagonal-arrayed, straight longitudinal channels to helical and CC mesostructures is achieved; such a transition has not been observed before in PMO materials. Our discovery is helpful in understanding the supramolecular cooperative assembly of hybrid materials and their structural and morphological evolution, which are important in the future applications of PMO materials.

Synthesis of urchin-like CdWO4 microspheres via a facile template free hydrothermal method

Urchin-like CdWO4 microspheres with hollow interiors have been successfully synthesized by a facile template free hydrothermal treatment method. The urchin-like CdWO4 hollow spheres are composed of radiatively assembled single-crystalline CdWO4 nanorods with lengths of several hundred nm and widths of 25–80 nm. The samples exhibit a blue-green emission in the range of 450–500 nm with the emission peak centered around 470 nm when excited at 293 nm. The effects of the preparation conditions such as the hydrothermal synthesis temperature, hydrothermal synthesis time, and the dosage of urea on the crystalline phase as well as morphology of final products have been systematically investigated. The successful synthesis of CdWO4 with a uniform urchin-like morphology relies on not only the choice of peroxo-polytungstic acid precursor, but also a controlled pH adjustment with the help of urea, both of which contribute to a homogenous nucleation and crystal growth process. It is also found that increasing the synthesis temperature, time and dosage of urea will enhance the photoluminescence (PL) emission of resultant materials. Our contribution provides a simple approach to synthesize CdWO4 materials with hierarchical architectures and potential applications as detectors in X-ray devices.

Evolution of Helical Mesostructures

An intriguing evolution from a simple internal helix to a hierarchical helical (HH) mesostructure with both internal and external helices or a complicated screwlike and concentric circular (CC) mesostructure is successfully observed. The complicated helical structures are determined by TEM studies and 3D electron tomography. We demonstrate a topological helix-coil transition between the internal and external helices to reveal the origin of the HH mesostructure and the relationship between the straight helical and HH rods. Moreover, the boundary condition of the helix-coil transition is clarified to explain in detail the formation of complex helical structures, such as the screwlike mesostructure. It is proposed that the final structural characteristics are determined exactly by the balance between the decrease in the surface free energy and the maintenance of the hexagonal packing in one individual rod, which explains the formation of unusual CC, HH, and screwlike morphologies in one pot. Our success has opened new opportunities in the characterization of complex porous architectures, thus paving a way to remarkable advances in the fields of synthesis, understanding, and application of novel porous materials.