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1.
Adv Mater ; : e1904836, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566280

RESUMO

Photothermal therapy triggered by near-infrared light in the second biowindow (NIR-II) has attracted extensive interest owing to its deeper penetration depth of biological tissue, lower photon scattering, and higher maximum permissible exposure. In spite of noble metals showing great potential as the photothermal agents due to the tunable localized surface plasmon resonance, the biological applications of platinum are rarely explored. Herein, a monocomponent hollow Pt nanoframe ("Pt Spirals"), whose superstructure is assembled with three levels (3D frame, 2D layered shells, and 1D nanowires), is reported. Pt Spirals exhibit outstanding photothermal conversion efficiency (52.5%) and molar extinction coefficients (228.7 m2 mol-1 ) in NIR-II, which are much higher than those of solid Pt cubes. Simulations indicate that the unique superstructure can be a significant cause for improving both adsorption and the photothermal effect simultaneously in NIR-II. The excellent photothermal effect is achieved and subsequently verified in in vitro and in vivo experiments, along with superb heat-resistance properties, excellent photostability, and a prominent effect on computed tomography (CT) imaging, demonstrating that Pt Spirals are promising as effective theranostic platforms for CT imaging-guided photothermal therapy.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31642157

RESUMO

In this paper, we describe a robust self-template strategy for facile and large-scale synthesis of porous multishell Au with controllable shell number, sphere size and in-situ surface modification. The process involved the rapid reduction of novel Au-melamine colloidal templates with a great amount of NaBH 4 in presence of poly(sodium-p-styrenesulfonate) (PSS). After soaking the templates in other metal salt solution, the obtained bimetallic templates could also be generally converted into bimetallic multishell structures by same reduction process. In the hydrogenation of 4-nitrostyrene using NH 3 BH 3 as a reducing agent, the porous triple-shell Au with surface modification (S-PTSAu) exhibited excellent selectivity (97 %) for 4-aminostyrene in contrast with unmodified triple-shell Au. Furthermore, it also showed higher enhancement of catalytic activity under irradiation of visible light as compared to similar catalysts with less shell number. This work opens up a new route in designing and synthesizing Au-based multishell structures for various applications.

3.
Small ; 15(43): e1903182, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31490623

RESUMO

Inspired by bio-enzymes, multistep cascade reactions are highly attractive in catalysis. Despite extensive research in recent years, it remains a challenge to promote the stability and activity of catalysts. Here, well-defined core-shell structured Ag-Au nanocage@CeO2 (Ag-Au NC@CeO2 ) are designed by a simple and facile self-assembly method. The results indicate that the Ag-Au NC@CeO2 has glucose oxidase-like activity and intrinsic peroxidase-like activity at the same time. As expected, Ag-Au NC@CeO2 hybrid nanomaterials exhibit cascade reactions activity. Moreover, the hybrid materials are promising to detect glucose without bio-enzymes. This research has potential applications in biomedicine and biomimetic catalysis.

4.
Nanoscale ; 11(27): 12932-12937, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31259328

RESUMO

The fabrication of a bimetallic core and ceria shell nanostructure is considered a promising way to promote catalytic performance and stability. Here, we report an Au-Pd@CeO2 core-shell structure with a tunable Au/Pd ratio through a self-assembly autoredox reaction approach. This process involves the sequence reduction of Au and Pd precursors and then self-assembly of CeO2 nanoparticles to encapsulate the noble metal core. The as-obtained samples exhibit excellent activity and selectivity towards the ammonia borane initiated hydrogenation of phenylacetylene with an enhanced stability owing to the protection from outside CeO2 nanoparticles. Through the construction of an Au-Pd bimetallic structure, an electron modification of Pd due to charge transfer between Au and Pd results in an enhanced catalytic performance. Such a strategy is promising for the synthesis of other bimetallic noble core and ceria shell structures for further applications.

5.
Nano Lett ; 19(8): 5093-5101, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31242732

RESUMO

Due to the limitation of inorganic nanomaterials in present clinical applications induced by their inherent nonbiodegradability and latent long-term side effects, we successfully prepared double switch degradable and clearable trinickel monophosphide porous hollow nanospheres (NiP PHNPs) modified with bovine serum albumin (BSA). Attributed to their acidic and oxidative double switch degradation capacities, NiP PHNPs can be effectively excreted from mice without long-term toxicity. Moreover, because of the paramagnetic and high molar extinction coefficient property resulting from the strong absorption in the second near-infrared light (NIR II) biowindow, NiP PHNPs have potential to be used for photoacoustic imaging (PAI) and T1-weighted magnetic resonance imaging (MRI) guided photothermal ablation of tumors in the NIR II biowindow. Specifically, it is interesting that the hollow structure and acidic degradation property enable NiP PHNPs to act as intelligent drug carriers with an on-demand release ability. These findings highlight the great potential of NiP PHNPs in the cancer theranostics field and inspire us to further broaden the bioapplications of transition metal phosphides.

6.
Angew Chem Int Ed Engl ; 58(30): 10204-10208, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31127675

RESUMO

Bipolar redox organics have attracted interest as electrode materials for energy storage owing to their flexibility, sustainability and environmental friendliness. However, an understanding of their application in all-organic batteries, let alone dual-ion batteries (DIBs), is in its infancy. Herein, we propose a strategy to screen a variety of phthalocyanine-based bipolar organics. The self-polymerizable bipolar Cu tetraaminephthalocyanine (CuTAPc) shows multifunctional applications in various energy storage systems, including lithium-based DIBs using CuTAPc as the cathode material, graphite-based DIBs using CuTAPc as the anode material and symmetric DIBs using CuTAPc as both the cathode and anode materials. Notably, in lithium-based DIBs, the use of CuTAPc as the cathode material results in a high discharge capacity of 236 mAh g-1 at 50 mA g-1 and a high reversible capacity of 74.3 mAh g-1 after 4000 cycles at 4 A g-1 . Most importantly, a high energy density of 239 Wh kg-1 and power density of 11.5 kW kg-1 can be obtained in all-organic symmetric DIBs.

7.
Adv Mater ; 31(16): e1807876, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30843288

RESUMO

The construction of refined architectures plays a crucial role in performance improvement and application expansion of advanced materials. The synthesis of carbon microspheres with a refined hierarchical structure is still a problem in synthetic methodology, because it is difficult to achieve the necessary delicate control of the interior structure and outer shell across the microscale to nanoscale. Nitrogen-doped multichamber carbon (MCC) microspheres with a refined hierarchical structure are realized here via a surfactant-directed space-confined polymerization strategy. The MCC precursor is not the traditional phenolic resol but a new kind of 2,6-diaminopyridine-based multichamber polymer (MCP) with a high nitrogen content up to 20 wt%. The morphology and sizes of MCP microspheres can be easily controlled by a dual-surfactant system. The as-synthesized MCC with a highly microporous shell, a multichamber inner core, and beneficial N-doping can serve as a promising supercapacitor material.

8.
Angew Chem Int Ed Engl ; 58(8): 2407-2412, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30600877

RESUMO

The stringent reaction conditions for an effective Fenton reaction (pH range of 3-4) hinders its application in cancer therapy. Therefore, how to improve the efficiency of the Fenton reaction in a tumor site has been the main obstacle in chemodynamic therapy (CDT). Herein, we report biocompatible one-dimensional (1D) ferrous phosphide nanorods (FP NRs) with ultrasound (US)- and photothermal (PT)-enhanced Fenton properties and excellent photothermal conversion efficiency (56.6 %) in the NIR II window, showing synergistic therapeutic properties. Additionally, the high photothermal conversion efficiency and excellent traverse relaxivity (277.79 mm-1 s-1 ) of the FP NRs means they are excellent photoacoustic imaging (PAI) and magnetic resonance imaging (MRI) agents. This is the first report on exploiting the response of metallic phosphides to NIR II laser (1064 nm) and ultrasound to improve the CDT effect with a high therapeutic effect and PA/MR imaging.

9.
Chem Sci ; 9(38): 7569-7574, 2018 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-30319758

RESUMO

By integrating redox self-assembly and redox etching processes, we report a general one-pot strategy for the synthesis of Au@multi-M x O y (M = Co, Ce, Fe, and Sn) yolk@shell nanospheres. Without any additional protecting molecule or reductant, the whole reaction is a clean redox process that happens among the inorganic metal salts in an alkaline aqueous solution. By using this method, Au@Co3O4/CeO2 (Au@Co-Ce), Au@Co3O4/Fe2O3 (Au@Co-Fe), and Au@CeO2/SnO2 (Au@Ce-Sn) yolk@shell nanospheres with binary oxides as shells, Au@Co3O4/CeO2/Fe2O3 (Au@Co-Ce-Fe) yolk@shell nanospheres with ternary oxides as shells and Au@Co3O4/CeO2/Fe2O3/SnO2 (Au@Co-Ce-Fe-Sn) yolk@shell nanospheres with quaternary oxides as shells can be obtained. Subsequently, the catalytic CO oxidation was selected as the catalytic model, and the Au@Co-Ce system was chosen as the catalyst. It was found that the catalytic activity of Au@Co-Ce yolk@shell nanospheres can be optimized by altering the relative proportion of Co and Ce oxides.

10.
Chem Sci ; 9(25): 5640-5645, 2018 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-30061997

RESUMO

Transition-metal Mo-based materials have been considered to be among the most effective hydrogen evolution reaction (HER) electrocatalysts. Regulating the electronic structure of Mo atoms with guest metal atoms is considered as one of the important strategies to improve their HER activity. However, introduction of guest metal elements in the vicinity of Mo sites with atomic-level hybridization is difficult to realize, resulting in the failure of the modified electronic structure of Mo sites. Herein, an Fe1.89Mo4.11O7/MoO2 material is prepared through the thermal treatment of a ferrimolybdate precursor. It exhibits a Tafel slope of 79 mV dec-1 and an exchange current density of 0.069 mA cm-2 in 1 M KOH medium, as well as a Tafel slope of 47 mV dec-1 and an exchange current density of 0.072 mA cm-2 in 0.5 M H2SO4 medium. Compared to original Mo-based oxides, Fe1.89Mo4.11O7 with the regulated Mo electronic structure shows a more suitable Mo-H bond strength for the fast kinetics of the HER process. Density functional theory (DFT) calculations also indicate that the Mo-H bond strength in Fe1.89Mo4.11O7 is similar to the Pt-H bond strength, resulting in the high kinetic activity of Mo-based HER electrocatalysts in alkaline and acidic media.

11.
Chemistry ; 24(58): 15649-15655, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30028548

RESUMO

High-quality (Pd cube)@(Pt helix) core@shell nanoparticles, with a novel spiral-structured shell and highly-ordered tangential channels are successfully fabricated through a facile wet chemistry method with the help of N,N-dimethyloctadecyl ammonium bromide acetate sodium (OTAB-Na). A bottom-up synthesis strategy provides accurate control of layers by simply changing the molar ratio of Pt/Pd with a uniform layer thickness of 2 nm maintained in all (1-3)-rounds samples. The irregular Pt superstructures of the shells, and sophisticated core@shell hybrid materials endow the as-produced samples with highly enhanced catalytic properties, when evaluated for hydrogenation of nitrobenzene as a probe reaction.

12.
Adv Mater ; 30(30): e1801726, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29889322

RESUMO

An experimental design, based on a combination of core-shell-structured upconversion nanoparticles and diarylethene photochromic molecules, for achieving rewritable optical memory is reported. This core-shell design enables the nanoparticles to emit two sets of distinct emission bands with ultrahigh spectral purity through laser excitation at 980 and 1532 nm. Importantly, the ultraviolet emission of the nanoparticles under 980 nm irradiation is used to activate the cyclization reaction of diarylethene through CC bond formation, while the green emission from the nanoparticles upon 1532 nm excitation leads to the cleavage of the newly formed CC bond. This pathway offers a convenient and versatile optical method for controlling the process of data writing and erasing with high spatiotemporal resolution.

13.
Chem Soc Rev ; 47(17): 6473-6485, 2018 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-29901043

RESUMO

The precise control over the luminescence profile of lanthanide-doped upconversion nanomaterials is of fundamental importance for their applications in wide-ranging fields of research. Conventional chemical approaches can lead to color-tunable emissions, but they generally require stringent modification either on dopant composition or doping concentration. In this Tutorial Review, we highlight a number of complementary methods that offer remote dynamic modulation of upconversion luminescence across the visible spectrum. This review serves to provide a summary of existing guidelines for controlling the emission spectrum of upconversion nanocrystals with fixed materials composition. The review will also discuss the major approaches to manipulating excitation energies and consider likely research challenges for further development of the field at the interface between nanotechnology and biological science.

14.
ACS Nano ; 12(5): 4886-4893, 2018 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-29727164

RESUMO

Despite regulation of the reactive oxygen species (ROS) level is an intelligent strategy for cancer therapy, the therapeutic effects of ROS-mediated therapy (including photodynamic therapy (PDT) and chemodynamic therapy (CDT)) are limited by oxygen reliance, inherent flaws of traditional photosensitizers, and strict reaction conditions of effective Fenton reaction. Herein, we reported biocompatible copper ferrite nanospheres (CFNs) with enhanced ROS production under irradiation with a 650 nm laser through direct electron transfer and photoenhanced Fenton reaction and high photothermal conversion efficiency upon exposure to an 808 nm laser, exhibiting a considerable improved synergistic treatment effect. Importantly, by exploiting the properties of O2 generation and glutathione (GSH) depletion of CFNs, CFNs relieve the hypoxia and antioxidant capability of the tumor, achieving photoenhanced CDT and improved PDT. The high relaxivity of 468.06 mM-1 s-1 enables CFNs to act as an outstanding contrast agent for MRI in vitro and in vivo. These findings certify the potential of such "all in one" nanotheranostic agent integrated PDT, photoenhanced CDT, photothermal therapy (PTT), and MRI imaging capabilities along with modulating the tumor microenvironment function in theranostics of cancer.

15.
Adv Mater ; : e1801211, 2018 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-29782694

RESUMO

Rational design of complex metal-organic framework (MOF) hybrid precursors offers a great opportunity to construct various functional nanostructures. Here, a novel MOF-hybrid-assisted strategy to synthesize Co3 O4 /Co-Fe oxide double-shelled nanoboxes is reported. In the first step, zeolitic imidazolate framework-67 (ZIF-67, a Co-based MOF)/Co-Fe Prussian blue analogue (PBA) yolk-shell nanocubes are formed via a facile anion-exchange reaction between ZIF-67 nanocube precursors and [Fe(CN)6 ]3- ions at room temperature. Subsequently, an annealing treatment is applied to prepare Co3 O4 /Co-Fe oxide double-shelled nanoboxes. Owing to the structural and compositional benefits, the as-derived Co3 O4 /Co-Fe oxide double-shelled nanoboxes exhibit enhanced electrocatalytic performance for oxygen evolution reaction in alkaline solution.

16.
Chemistry ; 24(39): 9765-9768, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29779256

RESUMO

Bi2 Te3 hierarchical nanostrings have been synthesized through a solvothermal approach with the assistance of sucrose. The hierarchical Bi2 Te3 was supposed to be fabricated through a self-assembly process. Te nanorods first emerge with the reduction of TeO32- followed by heterogeneous nucleation of Bi2 Te3 nanoplates on the surface and tips of Te nanorods. Te nanorods further transform into Bi2 Te3 nanorods simultaneously with the nanoplates' growth leading to a hierarchical structure. By controlling the reaction kinetics by adding different amount of ethylene glycol, the length of nanorods and the number of nanoplates could be tailored. The use of sucrose is vital to the formation of hierarchical structure because it not only serves as a template for the well-defined growth of Te nanorods but also promotes the heterogeneous nucleation of Bi2 Te3 in the self-assembly process. The Bi2 Te3 nanomaterial shows a moderate thermoelectric performance because of its hierarchical structure. This study shows a promising way to synthesize Bi2 Te3 -based nanostructures through environmental friendly approach.

17.
Small ; 14(20): e1704035, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29665268

RESUMO

Metal-organic frameworks (MOFs) with tunable compositions and morphologies are recognized as efficient self-sacrificial templates to achieve function-oriented nanostructured materials. Moreover, it is urgently needed to develop highly efficient noble metal-free oxygen evolution reaction (OER) electrocatalysts to accelerate the development of overall water splitting green energy conversion systems. Herein, a facile and cost-efficient strategy to synthesize Co9 S8 nanoparticles-embedded N/S-codoped carbon nanofibers (Co9 S8 /NSCNFs) as highly active OER catalyst is developed. The hybrid precursor of core-shell ZIF-wrapped CdS nanowires is first prepared and then leads to the formation of uniformly dispersed Co9 S8 /N, S-codoped carbon nanocomposites through a one-step calcination reaction. The optimal Co9 S8 /NSCNFs-850 is demonstrated to possess excellent electrocatalytic performance for OER in 1.0 m KOH solution, affording a low overpotential of 302 mV to reach the current density of 10 mA cm-2 , a small Tafel slope of 54 mV dec-1 , and superior long-term stability for 1000 cyclic voltammetry cycles. The favorable results raise a concept of exploring more MOF-based nanohybrids as precursors to induce the synthesis of novel porous nanomaterials as non-noble-metal electrocatalysts for sustainable energy conversion.

18.
Small ; 14(7)2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29325210

RESUMO

Design of new nanoagents that intrinsically have both diagnostic imaging and therapeutic capabilities is highly desirable for personalized medicine. In this work, a novel nanotheranostic agent is fabricated based on polydopamine (PDA)-functionalized Co-P nanocomposites (Co-P@PDA) for magnetic resonance imaging (MRI)-guided combined photothermal therapy and chemotherapy. The ultrahigh relaxivity of 224.61 mm-1 s-1 can enable Co-P@PDA to be applied as an excellent contrast agent for MRI in vitro and in vivo, providing essential and comprehensive information for tumor clinical diagnosis. Moreover, Co-P@PDA exhibit excellent photothermal performance owing to the strong near-infrared (NIR) absorbance of both Co-P nanocomposite and PDA. Highly effective ablation of tumors is achieved in a murine tumor model because the NIR laser not only induces photothermal effects but also triggers the chemotherapeutic drug on-demand release, which endows the Co-P@PDA with high curative effects but little toxicity and few side effects. These findings demonstrate that Co-P@PDA are promising agents for highly effective and precise antitumor treatment and warrant exploration as novel theranostic nanoagents with good potential for future clinical translation.

19.
Adv Mater ; 30(7)2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29315827

RESUMO

Due to the obvious distinctions in structure, core-shell nanostructures (CSNs) and yolk-shell nanostructures (YSNs) exhibit different catalytic behavior for specific organic reactions. In this work, two unique autoredox routes are developed to the fabrication of CeO2 -encapsulated Au nanocatalysts. Route A is the synthesis of well-defined CSNs by a one-step redox reaction. The process involves an interesting phenomenon in which Ce3+ can act as a weak acid to inhibit the hydrolysis of Ce4+ under the condition of OH- shortage. Route B is the fabrication of monodispersed YSNs by a two-step redox reaction with amorphous Co3 O4 as an in situ template. Furthermore, the transfer coupling of nitrobenzene is chosen as a probe reaction to investigate their catalytic difference. The CSNs can gradually achieve the conversion of nitrobenzene into azoxybenzene, while the YSNs can rapidly convert nitrobenzene into azobenzene. The different catalytic results are mainly attributed to their structural distinctions.

20.
Nanoscale ; 10(2): 825-831, 2018 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-29260827

RESUMO

Photothermal therapy (PTT) has attracted increasing interest and become widely used in cancer therapy owing to its noninvasiveness and low level of systemic adverse effects. However, there is an urgent need to develop biocompatible and multifunctional PTT agents with high photothermal conversion efficiency. Herein, biocompatible Cu-Ag2S/PVP nanoparticles (NPs) with strong near-infrared absorption and high photothermal conversion efficiency were successfully synthesized for high-performance photoacoustic (PA) imaging-guided PTT in vivo. The novel Cu-Ag2S/PVP NPs feature high photothermal conversion efficiency (58.2%) under 808 nm light irradiation, noticeably higher than those of most reported PTT agents. Because of their good dispersibility, Cu-Ag2S/PVP NPs passively accumulate within tumors via the enhanced permeability and retention effect, which can be confirmed by PA imaging, photothermal performance, and biodistribution in vivo. Furthermore, Cu-Ag2S/PVP NPs are thoroughly cleared through feces and urine within seven days, indicating a high level of biosafety for further potential clinical translation.

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