Selective deposition of a gadolinium(III) cluster in a hole opening of single-wall carbon nanohorn

Hashimoto, Ayako; Yorimitsu, Hideki; Ajima, Kumiko; Suenaga, Kazu; Isobe, Hiroyuki; Miyawaki, Jin; Yudasaka, Masako; Iijima, Sumio; Nakamura, Eiichi

doi:10.1073/pnas.0400596101

Cited by 104 publications

(108 citation statements)

References 26 publications

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“…The key factor of this achievement is therefore the introduction of surface thiol groups on supports. So far, with chemical methods, there have been some reports on structure formations resembling single atoms, such as the formation of a Pd monolayer (not isolated but connected atoms) at a single atom height on self-assembled monolayers (SAMs) [23] and a single Gd(III) complex in a hole opening of a single-walled carbon nanohorn, [24] but there has been no report on the formation of single atoms in a closely COMMUNICATIONS 2634 …”

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confidence: 99%

Formation of Single Pt Atoms on Thiolated Carbon Nanotubes Using a Moderate and Large‐Scale Chemical Approach

2006

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In recent years, nanoscience and nanotechnology have made rapid progress in utilizing material properties that differ from those of the bulk state as a result of the quantum size effect.[1] When researching a subject in nanoscience, the precise synthesis or formation of the nanometer-sized object is essential, regardless of the research discipline. The formation of metal clusters that are as small as possible has been a special challenge for numerous researchers, because it has been shown that size has remarkable effects on material properties, such as electrical, [2] optical, [3] thermal, [4] magnetic, [5] and catalytic [6] properties. These unique properties are expected to be maximized in the smallest metal cluster, i.e., a single metal atom, and such expectations have been proven in some research areas, such as single-electron transistors (SETs), [7,8] magnetic anisotropy energy (MAE), [9] and ballistic magnetoresistance (BMR).[10] However, in catalysis, maximized effects are still unclear, as the formation of enough single metal atoms on supports or substrates to apply to a practical catalysis reaction is quite difficult. This is in contrast to the case of SETs, MAE, and BMR, in which the size effects are easily detectable with even one atom. It is expected that single metal atoms could show the highest catalytic activity in a structureinsensitive reaction that requires no ensemble of atoms as an active site, although they could provide inferior performances in a structure-sensitive reaction, for example, the electrochemical oxygen-reduction reaction in which 3-4 nm is generally recognized to be the optimum size of particles. To date, the routes for the formation of single metal atoms or small metal clusters on supports or substrates can be divided into two categories: chemical and physical methods. Chemical methods, such as impregnation [11] and the colloidal method, [12] enable the formation of very small metal clusters on supports or substrates and have a fairly uniform size distribution. However, about 1 nm is generally considered to be the minimum size of clusters that can be achieved with these methods, although cluster formation below 1 nm has occasionally been reported. [13][14][15] Notably, there has been no report on the formation of single metal atoms (not ligated metal complexes such as H 2 Pt(IV)Cl 6 ) with these methods. In contrast, physical methods, such as sputtering, [16,17] thermal evaporation, [18][19][20] and scanning tunneling microscopy (STM) manipulation, [21,22] have been regarded as capable of forming and manipulating even single metal atoms on demand. However, both the number of single atoms that can be formed and the kind of substrates that can be used are fairly limited with these methods, because they require quite rigorous conditions, i.e., high vacuum and/or temperature as well as expensive and complicated facilities. These physical methods are therefore adequate to form single atoms for the qualitative investigation of their material properties, but are quite limited when it ...

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Formation of Single Pt Atoms on Thiolated Carbon Nanotubes Using a Moderate and Large‐Scale Chemical Approach

2006

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“…Thousands of SWNHox partially coalesce to form an 80-to 100-nm spherical aggregate (2), and this aggregate is expected to have enhanced permeability and retention properties (26,27) that make SWNHox effective for passive delivery of drugs to tumors. The holes of SWNHox observed with transmission electron microscopy (TEM) are 1-3 nm in diameter (28), and their pore sizes distributed in a range of 1-5 nm, showing a maximum at Ϸ2 nm (29), so that ZnPc [size: Ϸ1.4 nm (30)], similar to other molecules (7,8,(31)(32)(33), can pass into the SWNHox tubules. The edges of the SWNHox holes have many carboxyl groups that can be used to attach biological materials, such as proteins, to enhance the biocompatibility of SWNHox (34).…”

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confidence: 99%

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy

Zhang

Murakami

Ajima

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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252

186

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Multifunctionalization of carbon nanotubules is easily achieved by attaching functional molecules that provide specific advantages for microscopic applications. We fabricated a double photodynamic therapy (PDT) and photohyperthermia (PHT) cancer phototherapy system that uses a single laser. Zinc phthalocyanine (ZnPc) was loaded onto single-wall carbon nanohorns with holes opened (SWNHox), and the protein bovine serum albumin (BSA) was attached to the carboxyl groups of SWNHox. In this system, ZnPc was the PDT agent, SWNHox was the PHT agent, and BSA enhanced biocompatibility. The double phototherapy effect was confirmed in vitro and in vivo. When ZnPc-SWNHox-BSA was injected into tumors that were subcutaneously transplanted into mice, the tumors almost disappeared upon 670-nm laser irradiation. In contrast, the tumors continued to grow when only ZnPc or SWNHox-BSA was injected. We conclude that carbon nanotubules may be a valuable new tool for use in cancer phototherapy.carbon nanotubules ͉ drug carrier ͉ drug delivery system ͉ nanoparticle ͉ photohyperthermia

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“…Large clusters of about 2 nm diameter, consisting of one or several Gd(III) atoms bridged to oxygen anions located at the open holes of SWNH OX were formed as evidenced in Fig. 49 (Hashimoto et al 2004). Following a similar procedure, cisplatin (Pt(NH 3 ) 2 Cl 2 : CDDP), an anticancer drug, was incorporated inside the SWNHox (Ajima et al 2008).…”

Section: Functionalization and Applications Of Carbon Nanohornsmentioning

confidence: 99%

“…c Electron energy loss spectroscopy (EELS) of the Gd(III)M-edge (1185 and 1216 eV) of a cluster in a single SWNH, d A model of a 1.5 nm hole opening in a nanotube of 3.0 nm diameter containing a Gd cluster inside. e Illustration of the cluster growth mechanism in the interior of SWNHs (Hashimoto et al 2004) its thermal (non-catalytic or non-plasma activated) decomposition occurs at very high temperatures ([ 1200°C). This high temperature is not easily obtained in a typical CVD setup.…”

Section: Functionalization and Applications Of Carbon Nanohornsmentioning

confidence: 99%

Nanocarbon materials fabricated using plasmas

Hatakeyama

2017

Rev. Mod. Plasma Phys.

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Since the discovery of fullerenes more than three decades ago, new kinds of nanoscale materials of carbon allotropes called ''nanocarbons'' have so far been discovered or synthesized at successive intervals as cases such as carbon nanotubes, carbon nanohorns, graphene, carbon nanowalls, and a carbon nanobelt, while nanodiamonds were actually discovered before then. Their attractively excellent mechanical, physical, and chemical properties have driven researchers to continuously create one of the hottest frontiers in materials science and technology. While plasma states have often been involved in their discovery, on the other hand, plasma-based approaches to this exciting field originally hold promising and enormous potentials for advancing and expanding industrial/biomedical applications of nanocarbons of great diversity. This article provides an extensive overview on plasma-fabricated nanocarbon materials, where the term ''fabrication'' is defined as synthesis, functionalization, and assembly of devices to cover a wide range of issues associated with the step-by-step plasma processes. Specific attention has been paid to the comparative examination between plasma-based and non-plasma methods for fabricating the nanocarobons with an emphasis on the advantages of plasma processing, such as low-temperature/large-scale fabrication and diversitycarrying structure controllability. The review ends with current challenges and prospects including a ripple effect of the nanocarbon studies on the development of related novel nanomaterials such as transition metal dichalcogenides. It contains not only the latest progress in the field for cutting-edge scientists and engineers, but also the introductory guidance to non-specialists such as lower-class graduate students.& Rikizo Hatakeyama

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Selective deposition of a gadolinium(III) cluster in a hole opening of single-wall carbon nanohorn

Cited by 104 publications

References 26 publications

Formation of Single Pt Atoms on Thiolated Carbon Nanotubes Using a Moderate and Large‐Scale Chemical Approach

Formation of Single Pt Atoms on Thiolated Carbon Nanotubes Using a Moderate and Large‐Scale Chemical Approach

Fabrication of ZnPc/protein nanohorns for double photodynamic and hyperthermic cancer phototherapy

Nanocarbon materials fabricated using plasmas

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