著者

キム ジョンファン Singh Vidyadhar Cassidy Cathal Abild-Pedersen Frank Aranishi Kengo Kumar Sushant Lal Chhagan Gspan Christian Grogger Werner Sowwan Mukhles

雑誌

Nanoscale (ISSN:20403372)

巻号頁・発行日

vol.7, no.32, pp.13387-13392, 2015-08-28

被引用文献数

18

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We report on the design and synthesis of high performance catalytic nanoparticles with a robust geometry via magnetron-sputter inert-gas condensation. Sputtering of Pd and Mg from two independent neighbouring targets enabled heterogeneous condensation and growth of nanoparticles with controlled Pd core-MgO porous shell structure. The thickness of the shell and the number of cores within each nanoparticle could be tailored by adjusting the respective sputtering powers. The nanoparticles were directly deposited on glassy carbon electrodes, and their catalytic activity towards methanol oxidation was examined by cyclic voltammetry. The measurements indicated that the catalytic activity was superior to conventional bare Pd nanoparticles. As confirmed by electron microscopy imaging and supported by density-functional theory (DFT) calculations, we attribute the improved catalytic performance primarily to inhibition of Pd core sintering during the catalytic process by the metal-oxide shell.We report on the design and synthesis of high performance catalytic nanoparticles with a robust geometry via magnetron-sputter inert-gas condensation. Sputtering of Pd and Mg from two independent neighbouring targets enabled heterogeneous condensation and growth of nanoparticles with controlled Pd core-MgO porous shell structure. The thickness of the shell and the number of cores within each nanoparticle could be tailored by adjusting the respective sputtering powers. The nanoparticles were directly deposited on glassy carbon electrodes, and their catalytic activity towards methanol oxidation was examined by cyclic voltammetry. The measurements indicated that the catalytic activity was superior to conventional bare Pd nanoparticles. As confirmed by electron microscopy imaging and supported by density-functional theory (DFT) calculations, we attribute the improved catalytic performance primarily to inhibition of Pd core sintering during the catalytic process by the metal-oxide shell.

著者

キム ジョンファン Eguchi Haruki Ishikawa Yoshihiro

雑誌

Nanoscale (ISSN:20403372)

巻号頁・発行日

vol.9, no.26, pp.9071-9082, 2017-07-06

被引用文献数

11

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Ultrafine Au quantum clusters (QCs) were synthesized by etching host Au nanoparticles in the presence of ethylenediamine (en) and exhibited both strong photoluminescence (PL) and specific anticancer activity. The cutting-edge feature of this QC compound comprises subnanometer-size rhombohedral Au, which consists of 8 units of the anticancer motif, namely, an Au(en) complex (Au(en)QCs), which contributes to photo- and physicochemical stability as well as subcellular theranostic activity in intracellular PL imaging and in situ targeting. Moreover, the Au(en)QCs can be surface-encapsulated by transferrins (Tf) to create TfAu(en)QCs as a multipurpose drug carrier owing to numerous merits, which include cancer-selective biolabeling, high loading/release efficiency, high activity against drug-resistant tumor cells, low toxicity to normal cells, and physiological stability against biothiols, e.g., glutathiones. These versatile features, which are due to intrinsic optical and anticancer properties, provide potential as a single-drug delivery PL probe for preclinical applications, which has yet to be achieved using conventional nanoclusters.Ultrafine Au quantum clusters (QCs) were synthesized by etching host Au nanoparticles in the presence of ethylenediamine (en) and exhibited both strong photoluminescence (PL) and specific anticancer activity. The cutting-edge feature of this QC compound comprises subnanometer-size rhombohedral Au, which consists of 8 units of the anticancer motif, namely, an Au(en) complex (Au(en)QCs), which contributes to photo- and physicochemical stability as well as subcellular theranostic activity in intracellular PL imaging and in situ targeting. Moreover, the Au(en)QCs can be surface-encapsulated by transferrins (Tf) to create TfAu(en)QCs as a multipurpose drug carrier owing to numerous merits, which include cancer-selective biolabeling, high loading/release efficiency, high activity against drug-resistant tumor cells, low toxicity to normal cells, and physiological stability against biothiols, e.g., glutathiones. These versatile features, which are due to intrinsic optical and anticancer properties, provide potential as a single-drug delivery PL probe for preclinical applications, which has yet to be achieved using conventional nanoclusters.

著者

キム ジョンファン

雑誌

RSC Advances = RSC Advances (ISSN:20462069)

巻号頁・発行日

vol.21, pp.17179-17187, 2016-06

被引用文献数

17

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Inspired by the responsive characteristics of natural fibrous counterparts, triple stimuli, pH-, drug-, and near-infrared (NIR) light-responsive Janus composite nanosheets (JCNs) were investigated. The nanosheets consisted of gold islands sequentially hetero-grafted with three different biocompatible polymers (gum arabic, chitosan, and poly(ε-caprolactone)-b-polyethylene glycol (PEG-b-PCL)) that are hierarchically synthesized by a physical deposition–surface functionalization–chemical exfoliation processes. The JCNs are elastic and go through pH-controlled shape recovery activity in a reversible manner. Remarkably, by anchoring the heat-sensitive PEG-b-PCL on the chitosan side of JCNs, the JCNs are securely self-scrolled when doxorubicin molecules are loaded; and unscrolled to release the drug under remotely controlled NIR-irradiation, with negligible premature release, which mimics the structural behavior of a spore launcher in ferns. Moreover, the scrolled JCNs show exceptional photothermal stability under NIR-laser irradiation and the optical hyperthermal effect is capable of inducing death of tumor cells, as well as bright fluorescence and a targeted photothermal anti-tumor effect under two-photon fluorescence imaging. This enables complex nano-therapeutic drug vehicle development in potential cancer theranosis with low toxic side-effects.