Jinlou Gu

Facile Synthesis of Monodisperse Superparamagnetic Fe3O4 Core@hybrid@Au Shell Nanocomposite for Bimodal Imaging and Photothermal Therapy

A simple seed-mediated growth route is developed to fabricate monodisperse, uniform superparamagnetic Fe(3)O(4) core/gold shell structured nanocomposites with tunable sizes and optical properties, in which gold seed formation and attachment onto the core surface via S-Au covalent bonding proceeds almost simultaneously in the one-pot synthesis. The as-prepared nanocomposite is demonstrated to have a great potential for magnetic resonance imaging (MRI)-guided, focused photothermal tumor therapy under near-IR laser radiation.

Effective adsorption and enhanced removal of organophosphorus pesticides from aqueous solution by Zr-based MOFs of UiO-67.

Though many efforts have been devoted to the adsorptive removal of hazardous materials of organophosphorus pesticides (OPs), it is still highly desirable to develop novel adsorbents with high adsorption capacities. In the current work, the removal of two representative OPs, glyphosate (GP) and glufosinate (GF), was investigated by the exceptionally stable Zr-based MOFs of UiO-67. The abundant Zr-OH groups, resulting from the missing-linker induced terminal hydroxyl groups and the inherent bridging ones in Zr-O clusters of UiO-67 particles, served as natural anchorages for efficient GP and GF capture in relation with their high affinity toward phosphoric groups in OPs. The correlation between the most significant parameters such as contact time, OPs concentration, adsorbent dose, pH, as well as ionic strength with the adsorption capacities was optimized, and the effects of these parameters on the removal efficiency of GP and GF from the polluted aqueous solution were investigated. The adsorption of GP on UiO-67 was faster than that of GF, and a pseudo-second-order rate equation effectively described the uptake kinetics. The Langmuir model exhibited a better fit to adsorption isotherm than the Freundlich model. Thanks to the strong affinity and adequate pore size, the adsorption capacities in UiO-67 approached as high as 3.18 mmol (537 mg) g(-1) for GP and 1.98 mmol (360 mg) g(-1) for GF, which were much higher than those of many other reported adsorbents. The excellent adsorption characteristics of the current adsorbents toward OPs were preserved in a wide pH window and high concentration of the background electrolytes. These prefigured the promising potentials of UiO-67 as novel adsorbent for the efficient removal of OPs from aqueous solution.

A glucose-responsive controlled release of insulin system based on enzyme multilayers-coated mesoporous silica particles

A novel glucose-responsive controlled release of insulin system is constructed through coating enzyme multilayers on mesoporous silica particles (MSPs). The MSPs serve as the drug reservoir, and the enzyme multilayers cross-linked with glutaraldehyde act as a valve to control the release of insulin in response to the external glucose level.

Metal–organic frameworks with inherent recognition sites for selective phosphate sensing through their coordination-induced fluorescence enhancement effect

Luminescent metal–organic frameworks (LMOFs) have attracted significant attention as a unique class of sensing materials. In this work, the intrinsically fluorescent amino derivative of UiO-66 (UiO-66-NH2) was successfully exploited as a fluorescent probe for the sensitive and selective detection of phosphate anions in an aqueous medium. The inorganic Zr–O clusters and organic BDC-NH2 linkers in the elaborated UiO-66-NH2 MOFs were individually designed as phosphate recognition sites and signal reporters. The intrinsic fluorescence of BDC-NH2 was tuned from high to weak emission by ligand-to-metal charge transfer (LMCT) upon its integration into the framework of UiO-66-NH2 MOFs and this weakened fluorescence could be proportionally recovered in correlation with the applied phosphate level through a newly developed competitive coordination effect. The specificity for phosphate recognition of the employed sensory platform was scarcely affected by other possible interfering species. The efficacy of this strategy was demonstrated by a linear phosphate detection range of 5–150 μM and a limit of detection of 1.25 μM, which was far below the detection requirement of phosphate discharge criteria in the water environment. The possible sensing mechanisms for anionic phosphate detection using the currently established fluorescent probe, including host–guest interaction and structure–property correlation, were systematically investigated using XPS, FT-IR, XRD, TEM and N2 sorption techniques.

Rapid and Specific Aqueous-Phase Detection of Nitroaromatic Explosives with Inherent Porphyrin Recognition Sites in Metal–Organic Frameworks

Development of a rapid and effective method for the detection of 2,4,6-trinitrotoluene (TNT) in aqueous phase has attracted great attention. In this work, the fluorescent porphyrin-based metal-organic frameworks (MOFs) of PCN-224 were successfully exploited as a fluorescent probe for the rapid and selective TNT detection in water media. This strategy combined the advantages of fluorescent porphyrin molecules and porous MOFs, which not only overcame the aggregation of hydrophobic tetrakis(4-carboxyphenyl)porphyrin (TCPP) recognition sites but also promoted TNT to interact with recognition sites in virtue of the high surface and intrinsic open structure of MOFs. As a result, a rapid response time of as short as 30 s was obtained for the elaborated fluorescent probe. Meanwhile, the bright red emission of porphyrin units in PCN-224 could be proportionally quenched in correlation with the applied TNT level through the formation of TNT-TCPP complex in the ground state. The specificity of the employed sensory platform for TNT recognition was scarcely affected by other possible coexistent interfering species. Furthermore, this fluorescent PCN-224 probe presented a much higher quenching efficiency for TNT than other structurally similar nitroaromatic compounds and was successfully applied for the quantitative detection of TNT in the mixed nitroaromatic explosive samples. This prefigured their great potentials of practical TNT detection in water media for public safety and security.

Facile Synthesis of Magnetite/Perfluorocarbon Co‐Loaded Organic/Inorganic Hybrid Vesicles for Dual‐Modality Ultrasound/Magnetic Resonance Imaging and Imaging‐Guided High‐Intensity Focused Ultrasound Ablation

Multifunctional organic/inorganic hybrid nanovesicles, fabricated by a facile self-assembly/sol-gel approach, display a unique morphology (figure) and satisfactory stability under physiological conditions. By co-encapsulation of superparamagnetic magnetite nanoparticles and a liquid perfluorocarbon, the nanovesicles can be used not only as a dual-modality ultrasound/magnetic resonance contrast agent for accurate cancer diagnosis and monitoring, but also as a therapeutic enhancement agent for effective high-intensity focused ultrasound (HIFU) ablation.

Promotion effects of SiO2 or/and Al2O3 doped CeO2/TiO2 catalysts for selective catalytic reduction of NO by NH3

A series of the CeO2-based catalysts loaded on TiO2, TiO2-SiO2, TiO2-Al2O3, and TiO2-SiO2-Al2O3 supports were prepared by incipient impregnation method for the selective catalytic reduction (SCR) of NO by NH3 in the presence of oxygen. The SCR activities of the catalysts with different supports increases in the order of Ce/TiO2 < Ce/TiO2-20SiO2 ≈ Ce/TiO2-3.5Al2O3 < Ce/TiO2-20SiO2-3.5Al2O3. The Ce/TiO2-20SiO2-3.5Al2O3 catalyst showed 100% NO conversion in the temperature range of 250-425°C and 100% N2 selectivity in the whole temperature range. The catalytic activity of Ce/TiO2-20SiO2-3.5Al2O3 exhibited good stability and strong resistance to SO2 and H2O poisoning. The co-introduction of SiO2 and Al2O3 into TiO2 could increase the amount of chemisorbed oxygen and Lewis acid sites on the surface of catalyst, which should be responsible for the excellent SCR activity.

Sub-150 nm mesoporous silica nanoparticles with tunable pore sizes and well-ordered mesostructure for protein encapsulation

Despite their great potentials as biomacromolecues delivery vehicles, there are few, if any, reports on mesoporous silica nanoparticles (MSNs) simultaneously integrated with the merits of large pore size, small particle diameters and well-ordered mesostructure. Here, we designed a facile strategy for the synthesis of monodispersed MSNs using cationic surfactants (CSs) as templating agents, neutral amine of N,N-dimethylhexadecylamine (DMHA) as a pore size mediator and tri-block copolymer of F127 (EO106PO70EO106) as a particle growth inhibitor/dispersant. The obtained colloidal nanoparticles exhibited a highly ordered mesostructure and tunable pore diameter up to 4.6 nm (BJH) and monodispersed particle sizes less than 150 nm. A model protein of cytochrome c (CytC) was exemplified to be accommodated in the resultant MSNs and its loading amount was correlated with their pore size. The efficient cancer cellular uptake of the large-pore MSNs prefigured their potentials as intracellular delivery vehicles for membrane-impermeable proteins.

Defect creation in metal-organic frameworks for rapid and controllable decontamination of roxarsone from aqueous solution

Given the great harm to the human health of organic arsenic compounds (OACs), developing highly efficient adsorbents with both rapid adsorption rate and high saturation capacity is paramount important. Herein, Zr-based metal-organic frameworks (MOFs) of UiO-66 have been successfully exploited for the efficient decontamination of a typical organic arsenic compound of roxarsone (ROX) from aqueous solution. The influences of the most significant parameters such as contact time, adsorbate concentration, pH as well as ionic strength on the adsorption of ROX were investigated. The amount of missing-linker defects in UiO-66 was systematically tuned by changing the concentration of modulator in the reactants. The presence of the defects not only resulted in the dramatically enhanced porosity, but also induced the creation of ZrOH groups which served as the main active adsorption sites for efficient ROX sequestration. As a result, adsorptive capacity of ROX over UiO-66 could be improved to 730 mg/g, which was much higher than those of many reported adsorbents. Meanwhile, the adsorption equilibrium time could be reduced to as short as 30 min. These merits, combined with their excellent stability, prefigure the great potentials of these defect-tunable UiO-66 MOFs as adsorbents for the efficient removal of various OACs from the polluted water.

Controlled synthesis of multilayered gold nanoshells for enhanced photothermal therapy and SERS detection.

It can be streamlined: A facile and controllable approach for the fabrication of core/shell-structured multilayer gold nanoshells with uniform nanosize, monodispersity, and tunable plasmonic properties has been successfully developed by utilizing an organosilica layer as the dielectric spacer layer.