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1.
《应用有机金属化学》2017,31(11)
Materials having both magnetic and catalytic properties have shown great potential for practical applications. Here, a reduced graphene oxide/iron oxide/silver nanohybrid (rGO/Fe3O4/Ag NH) ternary material was prepared by green synthesis of Ag on pre‐synthesized rGO/Fe3O4. The as‐prepared rGO/Fe3O4/Ag NH was characterized using Fourier transform infrared spectroscopy, X‐ray diffractometry, Raman spectroscopy, vibrating sample magnetometry, transmission electron microscopy and energy‐dispersive X‐ray spectroscopy. rGO sheets were covered with Fe3O4 (8–16 nm) and Ag (18–40 nm) nanoparticles at high densities. The mass percentages were 13.47% (rGO), 62.52% (Fe3O4) and 24.01% (Ag). rGO/Fe3O4/Ag NH exhibited superparamagnetic behavior with high saturated magnetization (29 emu g−1 at 12 kOe), and efficiently catalyzed the reduction of 4‐nitrophenol (4‐NP) with a rate constant of 0.37 min−1, comparable to those of Ag‐based nanocatalysts. The half‐life of 4‐NP in the presence of rGO/Fe3O4/Ag NH was ca 1.86 min. rGO/Fe3O4/Ag NH could be magnetically collected and reused, and retained a high conversion efficiency of 94.4% after the fourth cycle. rGO/Fe3O4/Ag NH could potentially be used as a magnetically recoverable catalyst in the reduction of 4‐NP and environmental remediation. 相似文献
2.
Jingguo Li Hao Jiang Zhiqiang Yu Hongyan Xia Prof. Gang Zou Qijin Zhang Yue Yu 《化学:亚洲杂志》2013,8(2):385-391
Multimodal imaging and simultaneous therapy is highly desirable because it can provide complementary information from each imaging modality for accurate diagnosis and, at the same time, afford an imaging‐guided focused tumor therapy. In this study, indocyanine green (ICG), a near‐infrared (NIR) imaging agent and perfect NIR light absorber for laser‐mediated photothermal therapy, was successfully incorporated into superparamagnetic Fe3O4@mSiO2 core–shell nanoparticles to combine the merit of NIR/magnetic resonance (MR) bimodal imaging properties with NIR photothermal therapy. The resultant nanoparticles were homogenously coated with poly(allylamine hydrochloride) (PAH) to make the surface of the composite nanoparticles positively charged, which would enhance cellular uptake driven by electrostatic interactions between the positive surface of the nanoparticles and the negative surface of the cancer cell. A high biocompatibility of the achieved nanoparticles was demonstrated by using a cell cytotoxicity assay. Moreover, confocal laser scanning microscopy (CLSM) observations indicated excellent NIR fluorescent imaging properties of the ICG‐loaded nanoparticles. The relatively high r2 value (171.6 mM ?1 s?1) of the nanoparticles implies its excellent capability as a contrast agent for MRI. More importantly, the ICG‐loaded nanoparticles showed perfect NIR photothermal therapy properties, thus indicating their potential for simultaneous cancer diagnosis as highly effective NIR/MR bimodal imaging probes and for NIR photothermal therapy of cancerous cells. 相似文献
3.
Sodium‐Ion Storage Properties of FeS–Reduced Graphene Oxide Composite Powder with a Crumpled Structure
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Seung Yeon Lee Prof. Yun Chan Kang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(8):2769-2774
The sodium‐ion storage properties of FeS–reduced graphene oxide (rGO) and Fe3O4‐rGO composite powders with crumpled structures have been studied. The Fe3O4‐rGO composite powder, prepared by one‐pot spray pyrolysis, could be transformed to an FeS‐rGO composite powder through a simple sulfidation treatment. The mean size of the Fe3O4 nanocrystals in the Fe3O4‐rGO composite powder was 4.4 nm. After sulfidation, FeS nanocrystals of size several hundred nanometers were confined within the crumpled structure of the rGO matrix. The initial discharge capacities of the FeS‐rGO and Fe3O4‐rGO composite powders were 740 and 442 mA h g?1, and their initial charge capacities were 530 and 165 mA h g?1, respectively. The discharge capacities of the FeS‐rGO and Fe3O4‐rGO composite powders at the 50th cycle were 547 and 150 mA h g?1, respectively. The FeS‐rGO composite powder showed superior sodium‐ion storage performance compared to the Fe3O4‐rGO composite powder. 相似文献
4.
Core–Shell α‐Fe2O3@α‐MoO3 Nanorods as Lithium‐Ion Battery Anodes with Extremely High Capacity and Cyclability
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Qiang Wang Qi Wang De‐An Zhang Dr. Jing Sun Dr. Li‐Li Xing Prof. Xin‐Yu Xue 《化学:亚洲杂志》2014,9(11):3299-3306
α‐Fe2O3 nanoparticles are uniformly coated on the surface of α‐MoO3 nanorods through a two‐step hydrothermal synthesis method. As the anode of a lithium‐ion battery, α‐Fe2O3@α‐MoO3 core–shell nanorods exhibit extremely high lithium‐storage performance. At a rate of 0.1 C (10 h per half cycle), the reversible capacity of α‐Fe2O3@α‐MoO3 core–shell nanorods is 1481 mA h g?1 and a value of 1281 mA h g?1 is retained after 50 cycles, which is much higher than that retained by bare α‐MoO3 and α‐Fe2O3 and higher than traditional theoretical results. Such a good performance can be attributed to the synergistic effect between α‐Fe2O3 and α‐MoO3, the small size effect, one‐dimensional nanostructures, short paths for lithium diffusion, and interface spaces. Our results reveal that core–shell nanocomposites have potential applications as high‐performance lithium‐ion batteries. 相似文献
5.
Amorphizing of Ag Nanoparticles under Bioinspired One‐step Assembly of Fe3O4‐Ag/rGO Hybrids via Self‐redox Process with Enhanced Activity
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Songfang Zhao Haobo Jiang Jinhui Li Xiangying Meng Tianyu Chao Zhe Zhang Peng Zhang Yongju Gao Duxia Cao 《应用有机金属化学》2018,32(8)
Efficient and reusable nanocatalysts fabricated via a facile assembly are highly desirable for the cost‐effective hydrogenation reduction. Inspired by a fishing process with a fishnet, multifunctional nanostructured catalysts are rationally designed to combine interesting features via the self‐redox assembly of Fe3O4‐Ag composites on reduced graphene oxide (rGO) (Fe3O4‐Ag/rGO). In detail, Fe3O4 nanoparticles (NPs) endow the ternary hybrids with superparamagnetism (21.42 emu g?1), facilitating catalysts to be separated from the reaction system. rGO could provide electron transfer pathways, enhancing catalytic activity. More interestingly, GO and Ag+ could behave as oxidants to oxidize Fe2+ for the in situ assembly of Fe3O4‐Ag/rGO without any addition of reductant/oxidant or organic solvents, and AgNPs endow the ternary hybrids with excellent catalytic behaviour. Meaningfully, the bioinspired process enables the ternary hybrids to possess more abundant micro?/nanopores, larger surface area, and more amorphization. They exhibit exceptional catalytic performance, and could be recycled with excellent activity by means of convenient magnetic separation (at least 7 times). Moreover, the ternary hybrids could degrade methylene blue under UV light due to different valence states of Fe in Fe3O4. Therefore, the proposed bioinspired assembly and structure design for hierarchical catalysts would pave a promising way to assemble other catalysts. 相似文献
6.
Lingnan Chen Birong Zeng Yueguang Wu Jianjie Xie Shirong Yu Conghui Yuan Weiang Luo Yiting Xu Lizong Dai 《先进技术聚合物》2014,25(9):1069-1076
Magnetic composite nanospheres (MCS) were first prepared via mini‐emulsion polymerization. Subsequently, the hybrid core–shell nanospheres were used as carriers to support gold nanoparticles. The as‐prepared gold‐loading magnetic composite nanospheres (Au‐MCS) had a hydrophobic core embed with γ‐Fe3O4 and a hydrophilic shell loaded by gold nanoparticles. Both the content of γ‐Fe3O4 and the size of gold nanoparticles could be controlled in our experiments, which resulted in fabricating various materials. On one hand, the Au‐MCS could be used as a T2 contrast agent with a relaxivity coefficient of 362 mg?1 ml S?1 for magnetic resonance imaging. On the other hand, the Au‐MCS exhibited tunable optical‐absorption property over a wavelength range from 530 nm to 800 nm, which attributed to a secondary growth of gold nanoparticles. In addition, dynamic light scattering results of particle sizing and Zeta potential measurements revealed that Au‐MCS had a good stability in an aqueous solution, which would be helpful for further applications. Finally, it showed that the Au‐MCS were efficient catalysts for reductions of hydrophobic nitrobenzene and hydrophilic 4‐nitrophenol that could be reused by a magnetic separation process. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
7.
Hierarchical Fe3O4@poly(4‐vinylpyridine‐co‐divinylbenzene)@Au (Fe3O4@P(4‐VP–DVB)@Au) nanostructures were fabricated successfully by means of a facile two‐step synthesis process. In this study, well‐defined core–shell Fe3O4@P(4‐VP–DVB) microspheres were first prepared with a simple polymerization method, in which 4‐VP was easily polymerized on the surface of Fe3O4 nanoparticles by means of strong hydrogen‐bond interactions between ? COOH groups on poly(acrylic acid)‐modified Fe3O4 nanoparticles and a 4‐VP monomer. HAuCl4 was adsorbed on the chains of a P(4‐VP) shell and then reduced to Au nanoparticles by NaBH4, which were embedded into the P(4‐VP) shell of the composite microspheres to finally form the Fe3O4@P(4‐VP–DVB)@Au nanostructures. The obtained Fe3O4@P(4‐VP–DVB)@Au catalysts with different Au loadings were applied in the reduction of 4‐nitrophenol (4‐NP) and exhibited excellent catalytic activity (up to 3025 h?1 of turnover frequency), facile magnetic separation (up to 31.9 emu g?1 of specific saturation magnetization), and good durability (over 98 % of conversion of 4‐NP after ten runs of recyclable catalysis and almost negligible leaching of Au). 相似文献
8.
Jane Cathleen Gabunada Mohanraj Vinothkannan Dong Hee Kim Ae Rhan Kim Dong Jin Yoo 《Electroanalysis》2019,31(8):1507-1516
In this study, magnetite nanorods stabilized on polyaniline/reduced graphene oxide (Fe3O4@PANI/rGO) was synthesized via a wet‐reflux strategy. The possible formation of Fe3O4@PANI/rGO was morphologically and structurally verified by field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FT‐IR) spectroscopy, Raman spectroscopy, X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). Furthermore, the thermal stability of Fe3O4@PANI/rGO was measured by a thermogravimetric analyzer (TGA); the composite had good thermal stability owing to the ceramic nature of Fe3O4. The Fe3O4@PANI/rGO has been applied as a potential sensing platform for electrochemical detection of hydrogen peroxide (H2O2). By the combined efforts of extended active surface area, active carbon support, more catalytic active sites and high electrical conductivity, the Fe3O4@PANI/rGO exhibited an improved performance toward the non‐enzymatic detection of H2O2 in 0.5 M KOH with a fast response time (5 s), high sensitivity (223.7 μA mM?1 cm?2), low limit of detection (4.45 μM) and wide linear range (100 μM–1.5 mM). Furthermore, the fabricated sensor exhibited excellent recovery rates (94.2–104.0 %) during real sample analysis. 相似文献
9.
Chuang Nie Peng Du Hongwei Zhao Hainan Xie Yuxin Li Li Yao Yuanyuan Shi Lianna Hu Shaoyan Si Maonian Zhang Jianwen Gu Ling Luo Zaicheng Sun 《化学:亚洲杂志》2020,15(1):148-155
Melanoma is a primary reason of death from skin cancer and associated with high lethality. Photothermal therapy (PTT) has been developed into a powerful cancer treatment technique in recent years. Here, we created a low‐cost and high‐performance PTT agent, Ag@TiO2 NPs, which possesses a high photothermal conversion efficiency of ≈65 % and strong near‐infrared (NIR) absorption about 808 nm. Ag NPs were synthesized using a two‐step method and coated with TiO2 to obtain Ag@TiO2 NPs by a facile sol‐gel method. Because of the oxide, Ag@TiO2 NPs exhibit remarkable high photothermal conversion efficiencies and biocompatibility in vivo and in vitro. Cytotoxicity and therapeutic efficiency of photothermal cytotoxicity of Ag@TiO2 NPs were tested in B16‐F10 cells and C57BL/6J mice. Under light irradiation, the elevated temperature causes cell death in Ag NPs‐treated (100 μg mL?1) cells in vitro (both p<0.01). In the case of subcutaneous melanoma tumor model, Ag@TiO2 NPs (100 μg mL?1) were injected into the tumor and irradiated with a 808 nm laser of 2 W cm?2 for 1 minute. As a consequence, the tumor volume gradually decreased by NIR laser irradiation with only a single treatment. The results demonstrate that Ag@TiO2 NPs are biocompatible and an attractive photothermal agent for cutaneous melanoma by local delivery. 相似文献
10.
Synthesis of Ultrastable Ag Nanoplates/Polyethylenimine–Reduced Graphene Oxide and Its Application as a Versatile Electrochemical Sensor
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Jindi Wang Guoxin Zhang Wanxia Sun Jingsong Sun Dr. Liang Luo Dr. Zheng Chang Prof. Dr. Xiaoming Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10923-10929
Investigations on Ag nanostructures/reduced graphene oxide composites have been frequently reported, yet the morphology control of those loaded Ag nanocrystals is still challenging. We herein develop a facile method to grow triangular Ag nanoplates (AgP) on polyethylenimine‐modified reduced graphene oxide (AgP/PEI‐rGO). The AgP/PEI‐rGO hybrids show unexpected high stability against chloride ions (Cl?) and hydrogen peroxide (H2O2), which is possibly due to the strong interaction between surface Ag atoms with the amine groups of PEI. In the chronoamperometry measurements for detecting H2O2, N2H4, and NaNO2, the AgP/PEI‐rGO hybrid shows very wide linear ranges (usually 10?6–10?2 mol L?1 for H2O2, N2H4, and NaNO2) and low detection limits (down to ≈1×10?7 mol L?1), which demonstrate the promising electrochemical sensor applications of these metal/graphene hybrids with well‐defined morphologies and facets. In addition, this strategy could be extended to the deposition of other noble metals on rGO with controlled morphologies. 相似文献
11.
A simple and inexpensive immunosensor is reported for the rapid determination of Staphylococcus aureus B-1266 that uses Fe3O4–SiO2–NH2 nanoparticles as the direct signal label. The electrochemical immunoassay procedure includes the incubation of bacteria with excess magnetite nanoparticles, the magnetic separation of the free nanoparticles, a labeled immunocomplex formation on the surface of a planar electrode, and the electrochemical response from the magnetite nanoparticles in the immunocomplex. The electrochemical immunosensor allows for the selective and accurate detection of S. aureus from 10 to 105?CFU?mL?1 with a relative standard deviation lower than 10%. The limit of detection was 8.7?CFU?mL?1. 相似文献
12.
Mohammad Javad Aghagoli Mostafa Hossein Beyki 《International journal of environmental analytical chemistry》2017,97(14-15):1328-1351
Recently, MoS2 with abundant electron density in its structure attracted more attention as an adsorbent for environmental remediation. However, hard manipulation of target solution owing to high dispersibility in aqueous media restricts its application as adsorbent. Preparation of Fe3O4/MoS2 nanohybrid can solve this problem. Also, this nanohybrid improves adsorption capacities of target ions. In this work, Fe3O4 nanoparticles, MoS2 nanosheets and hybrid of these two were synthesised and then characterised by X-ray diffraction, energy-dispersive X-ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared spectra, Brunauer–Emmett–Teller surface area and vibrating sample magnetometer. Subsequently, adsorption of Ag(I) and Pb(II) ions from aqueous solution by these three adsorbents was examined in detail and compared with each other while the adsorption conditions including the pH value, contact time, dosage of sorbent, elution conditions and interfering ions have been optimised. According to obtained results, prepared nanohybrid showed enhanced adsorption capacities for both ions relative to naked Fe3O4 and MoS2. The limits of detection for Ag(I) and Pb(II) were calculated as 0.49 µg L?1 and 2.7 µg L?1, respectively, and the relative standard deviation percentages (n = 5) for Ag(I) and Pb(II) were 2.8%, and 3.0%, respectively. Furthermore, the preconcentration factors were 300 and 75 for Ag(I) and Pb(II) ions, respectively. Moreover, kinetic studies showed that pseudo-second-order model can better describe target analytes adsorption properties by every three adsorbents. Regeneration of the adsorbents was performed with HCl/thiourea mixture. 相似文献
13.
The Synthesis of Magnetic Lysozyme‐Imprinted Polymers by Means of Distillation–Precipitation Polymerization for Selective Protein Enrichment
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Jiali Cao Xihao Zhang Prof. Xiwen He Prof. Langxing Chen Prof. Yukui Zhang 《化学:亚洲杂志》2014,9(2):526-533
A protein imprinting approach for the synthesis of core–shell structure nanoparticles with a magnetic core and molecularly imprinted polymer (MIP) shell was developed using a simple distillation–precipitation polymerization method. In this work, Fe3O4 magnetic nanoparticles were first synthesized through a solvothermal method and then were conveniently surface‐modified with 3‐(methacryloyloxy)propyltrimethoxylsilane as anchor molecules to donate vinyl groups. Next a high‐density MIP shell was coated onto the surface of the magnetic nanoparticles by the copolymerization of functional monomer acrylamide (AAm), cross‐linking agent N,N′‐methylenebisacrylamide (MBA), the initiator azodiisobutyronitrile (AIBN), and protein in acetonitrile heated at reflux. The morphology, adsorption, and recognition properties of the magnetic molecularly imprinted nanoparticles were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and rebinding experiments. The resulting MIP showed a high adsorption capacity (104.8 mg g?1) and specific recognition (imprinting factor=7.6) to lysozyme (Lyz). The as‐prepared Fe3O4@Lyz‐MIP nanoparticles with a mean diameter of 320 nm were coated with an MIP shell that was 20 nm thick, which enabled Fe3O4@Lyz‐MIP to easily reach adsorption equilibrium. The high magnetization saturation (40.35 emu g?1) endows the materials with the convenience of magnetic separation under an external magnetic field and allows them to be subsequently reused. Furthermore, Fe3O4@Lyz‐MIP could selectively extract a target protein from real egg‐white samples under an external magnetic field. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(28):8222-8226
Janus nanoparticles (JNPs) offer unique features, including the precisely controlled distribution of compositions, surface charges, dipole moments, modular and combined functionalities, which enable excellent applications that are unavailable to their symmetrical counterparts. Assemblies of NPs exhibit coupled optical, electronic and magnetic properties that are different from single NPs. Herein, we report a new class of double‐layered plasmonic–magnetic vesicle assembled from Janus amphiphilic Au‐Fe3O4 NPs grafted with polymer brushes of different hydrophilicity on Au and Fe3O4 surfaces separately. Like liposomes, the vesicle shell is composed of two layers of Au‐Fe3O4 NPs in opposite direction, and the orientation of Au or Fe3O4 in the shell can be well controlled by exploiting the amphiphilic property of the two types of polymers. 相似文献
15.
利用种子生长法制备了磁性Fe2O3/Au/Ag复合纳米粒子,采用UV-vis和SEM对其光学性质以及表面结构的变化进行了表征.通过调节硝酸银的用量,制备了一系列具有不同Ag壳层厚度和表面结构的双金属外壳纳米粒子.以苯硫酚(TP)为探针分子,研究了不同Ag壳厚度的磁性纳米粒子的表面增强拉曼散射(SERS)活性.结果表明其SERS活性与表面结构的改变有关,在同时出现Ag和Au光学性质的Fe2O3/Au/Ag复合纳米粒子表面可观察到最强的SERS效应,这与表面的针孔效应以及Ag和Au之间的耦合增强作用有关.考察了Fe2O3/Au/Ag复合纳米粒子的磁富集作用,并利用SERS原位监测磁富集溶液中低浓度TP的能力,研究结果表明通过磁富集可提高SERS检测限,并且Fe2O3/Au/Ag的磁富集能力较Fe2O3/Au弱,但前者SERS信号较强. 相似文献
16.
Ag/mesoporous black TiO2 nanotubes heterojunctions (Ag‐MBTHs) were fabricated through a surface hydrogenation, wet‐impregnation and photoreduction strategy. The as‐prepared Ag‐MBTHs possess a relatively high specific surface area of ≈85 m2 g?1 and an average pore size of ≈13.2 nm. The Ag‐MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible‐light and near‐infrared (NIR) region. They exhibit excellent visible‐NIR‐driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi‐refraction, the Ti3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light‐harvesting and spatial separation of photogenerated electron–hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR‐enhanced visible‐NIR‐driven Ag‐MBTHs catalyst may provide new insights for designing other high‐performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials. 相似文献
17.
Dr. Zong‐Hong Lin Zih‐Yu Shih Prathik Roy Prof. Huan‐Tsung Chang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12330-12336
A facile approach has been developed for the preparation of various morphologies of Au–Ag2Te nanomaterials (NMs) that exhibit strong photocatalytic activity. Te NMs (nanowires, nanopencils, and nanorice) were prepared from TeO2 in the presence of various concentrations (16, 8, and 4 M ) of a reducing agent (N2H4) at different temperatures (25 and 60 °C). These three Te NMs were then used to prepare Au–Ag2Te NMs by spontaneous redox reactions with Au3+ and Ag+ ions sequentially. The Au–Ag2Te nanopencils exhibit the highest activity toward degradation of methylene blue and formation of active hydroxyl radicals on solar irradiation, mainly because they absorb light in the visible region most strongly. All three differently shaped Au–Ag2Te NMs (10 μg mL?1) provide a death rate of Escherichia coli greater than 80 % within 60 min, which is higher than that of 51 % for commercial TiO2 nanoparticles (100 μg mL?1). Under light irradiation, the Au NPs in Au–Ag2Te NMs enhance the overall photo‐oxidation ability of Ag2Te NMs through faster charge separation because of good contact between Ag2Te and Au segments. With high antibacterial activity and low toxicity toward normal cells, the Au–Ag2Te NMs hold great potential for use as efficient antibacterial agents. 相似文献
18.
Probing the Catalytic Activity of Reduced Graphene Oxide Decorated with Au Nanoparticles Triggered by Visible Light
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Dr. Jiale Wang Dr. Fabiane J. Trindade Caroline B. de Aquino Joana C. Pieretti Prof. Dr. Sergio H. Domingues Prof. Dr. Romulo A. Ando Prof. Dr. Pedro H. C. Camargo 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9889-9894
Hybrid materials in which reduced graphene oxide (rGO) is decorated with Au nanoparticles (rGO–Au NPs) were obtained by the in situ reduction of GO and AuCl4?(aq) by ascorbic acid. On laser excitation, rGO could be oxidized as a result of the surface plasmon resonance (SPR) excitation in the Au NPs, which generates activated O2 through the transfer of SPR‐excited hot electrons to O2 molecules adsorbed from air. The SPR‐mediated catalytic oxidation of p‐aminothiophenol (PATP) to p,p′‐dimercaptoazobenzene (DMAB) was then employed as a model reaction to probe the effect of rGO as a support for Au NPs on their SPR‐mediated catalytic activities. The increased conversion of PATP to DMAB relative to individual Au NPs indicated that charge‐transfer processes from rGO to Au took place and contributed to improved SPR‐mediated activity. Since the transfer of electrons from Au to adsorbed O2 molecules is the crucial step for PATP oxidation, in addition to the SPR‐excited hot electrons of Au NPs, the transfer of electrons from rGO to Au contributed to increasing the electron density of Au above the Fermi level and thus the Au‐to‐O2 charge‐transfer process. 相似文献
19.
Zhen Fan Dr. Dulal Senapati Sadia Afrin Khan Dr. Anant Kumar Singh Prof. Ashton Hamme Dr. Brian Yust Prof. Dhiraj Sardar Prof. Paresh Chandra Ray 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(8):2839-2847
Over the last few years, one of the most important and complex problems facing our society is treating infectious diseases caused by multidrug‐resistant bacteria (MDRB), by using current market‐existing antibiotics. Driven by this need, we report for the first time the development of the multifunctional popcorn‐shaped iron magnetic core–gold plasmonic shell nanotechnology‐driven approach for targeted magnetic separation and enrichment, label‐free surface‐enhanced Raman spectroscopy (SERS) detection, and the selective photothermal destruction of MDR Salmonella DT104. Due to the presence of the “lightning‐rod effect”, the core–shell popcorn‐shaped gold‐nanoparticle tips provided a huge field of SERS enhancement. The experimental data show that the M3038 antibody‐conjugated nanoparticles can be used for targeted separation and SERS imaging of MDR Salmonella DT104. A targeted photothermal‐lysis experiment, by using 670 nm light at 1.5 W cm?2 for 10 min, results in selective and irreparable cellular‐damage to MDR Salmonella. We discuss the possible mechanism and operating principle for the targeted separation, label‐free SERS imaging, and photothermal destruction of MDRB by using the popcorn‐shaped magnetic/plasmonic nanotechnology. 相似文献
20.
Majid Arvand Afshin Nickdoust Masouleh 《Journal of the Iranian Chemical Society》2017,14(8):1673-1682
Magnetic solid-phase extraction based on Fe3O4/graphene oxide nanocomposites was investigated for the separation, preconcentration and determination of imatinib and doxorubicin in aqueous solutions. Synthesis of Fe3O4/graphene oxide was characterized by transmission electron microscopy, energy-dispersive X-ray analyzer and vibrating sample magnetometer. After optimizing the conditions, optimal experimental conditions including sample pH, the amount of the magnetic nanoparticles, the effect of salt concentration and other chemotherapy medications, eluent type and extraction time were studied and established. The method showed good linearity for the determination of doxorubicin and imatinib in the concentration range of 0.01–100 μg mL?1 in aqueous solutions with limit of detection 1.8 ng mL?1 for doxorubicin and 1.9 ng mL?1 for imatinib. The relative recoveries of doxorubicin and imatinib levels were 96.7 and 88.4%, respectively. The results indicate that the present procedure is a suitable method for extraction of imatinib and doxorubicin from environmental water samples. 相似文献