bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioconjugated Iron-Filled Carbon Nanotubes As Cancer Theranostics Agents
Authors: Pineux Florent 
Published: February 2020

Magnetic nanoparticles (MNPs) and carbon nanotubes (CNTs) have emerged as two new classes of nanomaterials for simultaneous diagnostics and treatment (theranostics) of cancer. On one hand, MNPs can act as magnetic resonance imaging (MRI) contrast agents, magnetically-driven drug delivery cargoes, filtrations and selective separations of biological entities agents and magnetic fluid hyperthermia (MFH) treatments.[1] On the other hand, CNTs have been used against cancer as intracellular carriers for biologically relevant species[2] thanks to their large surface area and their faculty to penetrate cells or as infrared hyperthermia agents[3], among other possibilities.[4]

In order to combine the advantages of both parts, we synthesized in our group a hybrid composed of metallic iron nanoparticles filled in multiwall carbon nanotubes (Fe@CNTs) bioconjugated to the monoclonal antibody (mAb) Cetuximab. CNTs graphitic layers offers a protection against oxidation of iron nanoparticles, keeping them in more magnetically active phases whereas mAb targets epidermal growth factor receptor (EGFR) overexpressing A431 cancer cells. In a pilot study, we showed the in vitro efficiency of Fe@CNTs in selective targeting and elimination of A431 cells over control cell lines via magnetic filtration and hyperthermia.[5] We then studied in detail various Fe@CNTs possessing different phases of iron, in order to correlate their structural and magnetic properties onto their biological performances.[6]

In parallel we developed seminal work[7]led by our team about H-bonded supramolecular polymer (SMP) able to wrap around CNTs to exploit the potential of our Fe@CNTs as a non-covalent scaffold. We thus synthesized new pegylated H-bonded supramolecular polymers able to solubilize Fe@CNTs in aqueous media. Moreover, this polymer-CNTs nano-assembly shows interesting properties of reversible wrapping and un-wrapping under thermal stimulus, and is envisaged to be used for simultaneous MFH and triggered drug delivery treatments.
References:
[1] V. I. Shubayev, T. R. Pisanic, S. Jin, Adv. Drug Deliv. Rev.

2009
, 61, 467–77.
[2] H. Dai, Acc. Chem. Res.

2002
, 35, 1035–44.
[3] R. Singh, S. V Torti, Adv. Drug Deliv. Rev.

2013
, 1–16.
[4] C. Fabbro, H. Ali-Boucetta, T. Da Ros, K. Kostarelos, A. Bianco, M. Prato, Chem. Commun.

2012
, 48, 3911–26.
[5] R. Marega, F. De Leo, F. Pineux, J. Sgrignani, A. Magistrato, A. D. Naik, Y. Garcia, L. Flamant, C. Michiels, D. Bonifazi, Adv. Funct. Mater.

2013
, 23, 3173–3184.
[6] F. Pineux, M. Riccardo, A. Stopin, A. La Torre, Y. Garcia, C. Michiels, D. Bonifazi, Manuscript in preparation

[7] A. Llanes-Pallas, K. Yoosaf, H. Traboulsi, J. Mohanraj, T. Seldrum, J. Dumont, A. Minoia, R. Lazzaroni, N. Armaroli, D. Bonifazi, J. Am. Chem. Soc.

2011
, 133, 15412–24.
Figure : Scheme of an iron-filled Carbon Nanotube conjugated with a monoclonal antibody (Fe@CNT-mAb), wrapped with our supramolecular polymer.

Figure 1
(Invited) Single Carbon-Nanotube Photonics and Optoelectronics
Authors: Kato Yuichiro K. 
Published: February 2020

Single-walled carbon nanotubes have unique optical properties as a result of their one-dimensional structure. Not only do they exhibit strong polarization for both absorption and emission, large exciton binding energies allow for room-temperature excitonic luminescence. Furthermore, their emission is in the telecom-wavelengths and they can be directly synthesized on silicon substrates, providing new opportunities for nanoscale photonics and optoelectronics.
Here we discuss the use of individual single-walled carbon nanotubes for generation, manipulation, and detection of light on a chip. Their emission can be efficiently coupled to specially-designed silicon photonic-crystal nanobeam cavities [1]. With the strong absorption polarization at the nanoscale, they allow for unconventional polarization conversion that results in giant circular dichroism [2]. More recently, we have found that alternating gate-voltages can generate optical pulse trains from individual nanotubes [3]. Ultimately, these results may be combined to achieve further control over photons at the nanoscale.
Work supported by KAKENHI, The Canon Foundation, The Asahi Glass Foundation, JSPS Open Partnership Joint Projects, and the Photon Frontier Network Program of MEXT, Japan.
[1] R. Miura, S. Imamura, R. Ohta, A. Ishii, X. Liu, T. Shimada, S. Iwamoto, Y. Arakawa, Y. K. Kato, Nature Commun. 5, 5580 (2014).
[2] A. Yokoyama, M. Yoshida, A. Ishii, Y. K. Kato, Phys. Rev. X 4, 011005 (2014).
[3] M. Jiang, Y. Kumamoto, A. Ishii, M. Yoshida, T. Shimada, Y. K. Kato, arXiv:1407.7086.
Multi-Walled Carbon Nanotube Electrode Optimization for Thermocells
Authors: Holubowitch Nick , Lippert Cameron , Landon James , Liu Kunlei 
Published: February 2020

There is an abundance of rejected thermal energy in industrial settings available for conversion to electricity by devices such as thermocells. Compared to solid state thermoelectric technology, thermocells scavenge low-grade heat more efficiently and offer 10-fold greater Seebeck coefficients (ferro/ferricyanide α = -1.4 mV/K). Since aqueous ferrocyanide cells are thermodynamically constrained by the Seebeck coefficient, focus has shifted to optimizing their kinetic performance.
Nanocarbons, particularly multi-walled carbon nanotubes (MWNTs) are emerging as the favored active electrode material in thermocells (1-3). These offer high conductivity and large electrochemically active surface areas. The preparation of MWNT-based electrodes, however, is no trivial task and non-electrochemically active binder materials (e.g. PVDF) are nearly always required. A variety of methods for MWNT/PVDF electrode casting have been investigated but doctor blade and spray-coat methods are currently lowest cost and most commonly employed. In this study, we contribute to the on-going optimization of spray-coated MWNT/PVDF on Al electrodes by exploring the influence of mass loading and active material-binder content via characterization in functioning full thermocells.
While varying the MWNT/PVDF ratio had little impact on peak power densities, we found that the thinnest possible coatings (i.e. one coat) yielded the highest power density per mass of MWNTs at 290 W kg-1. This suggests that tortuosity and/or poor wettability (hydrophobicity) of the MWNT electrodes limit the penetration depth of aqueous ferro/ferricyanide ions during thermoelectric conversion. Therefore, if coating thickness is strictly controlled, only 0.08 mg cm-2 (in our case) is needed. This minimizes inactive bulk MWNTs and brings the previously prohibitively expensive MWNTs to a fraction of the cost of the ferro/ferricyanide electrolyte for thermal to electric energy harvesting. The findings may be of broader interest for the fabrication of any electrochemical cells where integration of MWNTs is desired.
Figure 1. Potential-current and power curves of thermocells for three thicknesses of spray-coated MWNT/PVDF electrodes on Al. Current and power are normalized by MWNT mass, where the thicknesses refer to loadings of 1.0, 0.23, and 0.08 mg cm-2 MWNTs at 50/50 MWNT/PVDF content by mass.
References
1. R. Hu, et al., Nano Letters, 10(3), 838 (2010).
2. T.J. Kang, et al., Advanced Functional Materials, 22(3), 477 (2012).
3. P.F. Salazar, S. Kumar, and B.A. Cola, Journal of the Electrochemical Society, 159(5), B483 (2012).

Figure 1
(Invited) Etching of Surfactant from Solution-Processed, Type-Separated Carbon Nanotubes and Impact on Device Behavior
Authors: Léonard François 
Published: February 2020

Semiconducting single-walled carbon nanotubes (SWCNTs) have great potential for use in electronic and optoelectronic devices. However, methods for synthesizing SWCNTs produce a mixture of metallic and semiconducting materials requiring additional processing to separate by electronic type. Purification and enrichment of the semiconducting fraction is readily achieved using centrifugation of aqueous suspensions of SWCNTs with the help of surfactants, but this leaves residual surfactant on the SWCNT surface that can impact their electronic and optical properties. Here, we present a detailed study of the sodium taurodeoxycholate (STDC) surfactant removal process during vacuum annealing and show that it occurs through fractionation of the surfactant and that complete removal requires exceedingly high temperatures, indicating strong binding to the SWCNTs. We then present an approach based on air oxidation and mild annealing to completely remove the surfactant while maintaining the SWCNT properties. Using this approach, we compare single-SWCNT electronic devices with and without STDC and show that despite the very strong surfactant binding it does not affect device performance substantially.
(Invited) Carbon Nanotubes: From the Origin of Helicity to Application
Authors: Harutyunyan Avetik R 
Published: February 2020

Despite recent advances in experimental studies on the preferential and helicity selective growths of carbon nanotubes the mechanism of helicity formation still remains elusive, which hinder further progresses in selective synthesis. Here we will present the results of the studies on nucleation of the carbon cap, believed to be responsible for the helicity of the surface catalyzed carbon nanotubes. We found that the cap formation involves graphene growth across various adjacent facets of catalyst particle and an explicit introduction of defects. As a result the graphene embryos incorporate in their hexagonic network various polygons to accommodate the curved 3D geometry that initiates carbon dome formation. Taking into account the census of nanotube cap and the fact that given cap fits only one nanotube wall we suggest that the carbon cap can serve as a precursor that sets the symmetry of growing tube.
Our recent progresses in production of carbon nanotubes, nanotube reinforced composites and their potential applications also will be presented.
Effects of Growth Substrates on Growth Mode of Carbon Nanofibers
Authors: Tian Meijuan , Zhang Qian , Zhang Cuixia , Dong Lifeng 
Published: February 2020

Excellent properties of carbon nanofibers, such as high electrical conductivity, high specific strength, and low mass density, have attracted lots of research interest. The realization of the controllable synthesis of carbon nanofibers is the final purpose through studying the growth mechanism, which has a close relation to reaction conditions for carbon fiber synthesis.
In this study, we have synthesized vapor grown carbon nanofibers on three types of substrates: graphite, ceramic, and titanium dioxide nanotube array, which were coated with copper salt catalyst precursors. Copper salt and acetylene were used as catalyst precursor and carbon source, respectively. The morphology and structure of the as-obtained product were analyzed using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). Experimental results demonstrate that the morphology of carbon fibers synthesized on graphite substrate is similar to that on the ceramic. However, carbon fibers with small diameters of about 20-40 nm were synthesized on the titanium dioxide nanotube arrays. This means, growth substrate plays important roles in the formation of catalyst particles and thereby affects the growth mode of carbon nanofibers.
(Invited) Aggregation State of Carbon Nanotubes in Solution
Authors: Okazaki Toshiya 
Published: February 2020

Because of their superior mechanical, optical, thermal and electrical properties, carbon nanotubes (CNTs) have been paid particular attention since their discovery. Although much progress has been made so far, it is widely recognized that the bottleneck for applications is to prepare the homogeneous dispersion of CNTs. Indeed the functionality of a wide range of applications depends on the individual CNTs rather than the CNT bundles. The evaluation of dispersion states of CNTs in solutions has therefore been one of the serious issues in the CNT community. Here we examine the dispersion and the aggregation states of (CNTs) solution by the several characterization techniques such as a centrifuge sedimentation analysis. The estimated particle size and distribution will be discussed as compared to the physical properties of the composite materials.

This paper is based on results obtained from a project commissioned by the New Energy and Industrial Technology Development Organization (NEDO).
Swnt-Sorting with a Removable Solubilizer Based on Dynamic Supramolecular Coordination Chemistry
Authors: Nakashima Naotoshi , Toshimitsu Fumiyuki 
Published: February 2020

Highly pure semiconducting single-walled carbon nanotubes (SWNTs) are essential for the next generation of electronic devices, such as field-effect transistors and photovoltaic applications, but contamination by metallic-SWNTs reduces the efficiency of their associated devices. Polyfluorene-based copolymers (PFOs)1, 2 have been intensively studied because they dissolve/extract only sem-SWNTs in toluene by a simple sonication method. We have previously demonstrated a rational method for the selective extraction of a specific chirality of the sem-(n,m) SWNTs using a series of systematically designed fluorene-based copolymers3-4. Moreover, we revealed that the PFO copolymers with a bulky optically active moiety could separate the right- and left-handed sem-SWNTs5. However, there are several serious problems when using PFOs; that is, difficulty in the removal of the wrapped PFOs from the SWNTs/PFO composites6, 7 as well as their low extraction efficiency from the as-produced SWNTs1,
2.
Here we report a simple and efficient method for the separation of semiconducting- and metallic-SWNTs based on supramolecular complex chemistry.8 We describe the synthesis of metal-coordination polymers (CP-M) composed of a fluorene-bridged bisphenanthroline ligand and metal ions. Based on a difference in the ‘solubility product’ of CP-M-solubilized semiconducting-SWNTs and metallic-SWNTs, we readily separated semiconducting-SWNTs. Furthermore, the CP-M polymers on the SWNTs were simply removed by adding a protic acid and inducing depolymerization to the monomer components. We also carried out molecular mechanics calculations to reveal the difference of binding and wrapping mode between CP-M/semiconducting-SWNTs and CP-M/metallic-SWNTs.
This study opens a new stage for the use of such highly pure semiconducting-SWNTs in many possible applications.

References

[1] Chen, F., Wang, B., Chen, Y., Li, L.-J. Nano Lett.
7, 3013–3017 (2007).
[2] Nish, A., Hwang, J., Doig, J., Nicholas, R. Nature Nanotech.
2, 640-646 (2007).
[3] Ozawa, H. et al.
J. Am. Chem. Soc.
133, 2651–2657 (2011).
[4] Ozawa, H., Ide, N., Fujigaya, T., Niidome, Y., Nakashima, N. Chem. Lett.
40, 239–241 (2011).
[5] Akazaki, K., Toshimitsu, F., Ozawa, H., Fujigaya, T., Nakashima, N. J. Am. Chem. Soc.
134, 12700–12707 (2012).
[6] Izard, N. et al., App. Phys. Lett.
92, 243112 (2008).
[7] Jakubka, F. et al., ACS Macro Lett.
1, 815–819 (2012).
[8] Toshimitsu, F., Nakashima, N. Nature Comm.,
2014, 5, art no. 5041.
High-Fidelity Single-Column Selective Separation of Swcnts
Authors: Zhao Yang , Clar Justin , Xu Jia , Yuan Tianyu , Bonzongo Jean-Claude J , Ziegler Kirk J 
Published: February 2020

Post-synthesis separation of single walled carbon nanotubes (SWCNTs) has been studied with great interest in the past decade. Among the most promising techniques, the selective adsorption of SWCNTs onto hydrogel stationary phases including both agarose and dextran provides opportunity for large-scale separations with relatively high purity. Recently, successful progresses have been achieved for further purification of semiconducting fractions separation into individual chiralities. However, severe limitations exist for large scale production including, minimal throughput, reproducibility, and hydrogel lifetime. Our previous work has highlighted the importance of surfactant structure along SWCNT sidewalls in the separation mechanism. Using our understanding of the mechanism, we have begun collecting both mono-chiral and near mono-chiral s-SWCNT fractions in a single column using a co-surfactant elution profile at a single temperature. Additionally, we report the effect of common preprocessing steps on the overall separation quality. Finally, it is again demonstrated that effective methods of hydrogel regeneration are a much needed area of further study.
(Invited) Interfacial Functionalization of Carbon Nanotubes: From Effective Charge Propagation and Storage to Enhancement of Electrocatalytic and Bioelectrocatalytic Properties
Authors: Kulesza Pawel J 
Published: February 2020

Of particular interest to the preparation of advanced materials is synthesis and characterization of carbon nanostructures (particularly nanotubes) or noble metal nanoparticles, their stabilization (e.g. through self-assembly), as well as organization into two-dimensional arrays and three-dimensional network films through controlled fabrication (e.g. sequential attraction). Thus functionalized nanosized materials with well-defined composition, structure and thickness can be formed. The interfaces can also be highly functionalized, and they can exhibit specific catalytic or unique electronic, charge storage, optical and sensing properties. We explore here the ability of inorganic structures to stabilize and derivatize carbon nanotubes. Among inorganic systems, polyoxometallates of molybdenum and tungsten are attractive since they can not only adsorb irreversibly on solid surfaces but also exhibit reversible stepwise multi-electron transfer reactions. The concept of the layer-by-layer formation of hybrid assemblies composed of anionic polyoxometallate-protected carbon nanotubes (or metal nanoparticles) and ultra-thin films of positively charged conducting polymers (e.g. PEDOT) or polycationic metal oxo species (e.g. zirconyl or vanadyl) will be described and discussed here. The resulting novel composite materials have been fabricated as thin or moderately thick (µm level) films on electrode surfaces. As evidenced from STM and scanning electron microscopy, their morphology is still granular but the structure is fairly dense. Further, they are characterized by fast dynamics of charge propagation. Obviously, this research is of importance to the construction of effectively operating charge storage devices (capacitors), charge mediators (e.g. in bioelectrochemistry), molecular electronic systems and electrocatalysis. In the latter case, polyoxometallates can also be applied to stabilize and link Pt-Ru, Pt-Sn and various alloyed Pt-based nanoparticles. It is apparent from diagnostic cyclic voltammetric, rotating disk voltammetric and chronoamperometric measurements that such systems exhibit attractive properties towards electroreduction of oxygen or carbon dioxide as well as oxidation of small organic molecules (ethanol, methanol or dimethyl ether). In addition to the fact that introduction of carbon nanotubes improves charge distribution at the electrocatalytic interface, further addition of metal oxide nanospecies can generate –OH groups at low potentials that induce oxidation of passivating CO adsorbates (e.g. on Pt); they can potentially break C-H or C-O bonds, as well as they can possibly weaken C-C bonds during ethanol oxidation (e.g. through changes of the electronic properties of Pt).
Observation of Efficient Upconversion Photoluminescence of Single-Walled Carbon Nanotubes
Authors: Miyauchi Yuhei , Matsuda Kazunari 
Published: February 2020

Because of their potential applications in optoelectronics and bioimaging, photoluminescence (PL) properties of single-walled carbon nanotubes (SWNTs) have attracted much attention over the past decade [1-3]. Here, we report a novel aspect of the PL properties of SWNTs: availability of near-infrared PL (~950-1000 nm) by excitation with longer wavelength light (>1100-1200 nm), namely, upconversion PL. On the basis of the observations of temperature and excitation photon energy dependence, the observed phenomenon is attributed to the efficient phonon-assisted exciton upconversion processes. Furthermore, we demonstrate that strong enhancement of the upconversion PL occurs with additional chemical treatment on SWNTs. Materials exhibiting efficient upconversion PL in the near infrared range have been strongly desired for the observation of deep inside of highly scattering biological media. Our findings may thus open the door to the application of SWNTs in upconversion imaging of unprecedentedly deep inside of biological tissues.
[1] Y. Miyauchi, J. Mater. Chem. C 1, 6499 (2013). [2] Y. Miyauchi, M. Iwamura, S. Mouri, T. Kawazoe, M. Ohtsu, and K. Matsuda, Nature Photon. 7, 715 (2013). [3] M. Iwamura, N. Akizuki, Y. Miyauchi, S. Mouri, J. Shaver, Z. Gao, L. Cognet, B. Lounis and K. Matsuda, ACS Nano, asap (2014).
Sensitization of Rare Earth Ions with Carbon Nanotube Plasmonic Antennas
Authors: Sofka Benjamin Joseph , Rotkin Slava V. 
Published: February 2020

Complexes containing rare earth ions (REI) and single-walled carbon nanotubes (SWNT) functionalized with single stranded DNA show promise to be utilized for the optical sensing of bio-molecules [1]. However, the electromagnetic interactions between the SWNT and the REI have not been sufficiently studied. In this work, we focus on the plasmonic interaction between the SWNT and a REI such as Terbium or Europium for their use as a biosensing complex.
The SWNT may act as a plasmonic antenna and generate a local field in the vicinity of the REI. We use the transmission line model [2] to model the plasmonic properties of the SWNT antenna. The incoming light induces a surface current distribution:
I(z)=(V0/Zc)sinh[γp(l/2-|z|)]
where V0 is the input voltage into the transmission line model determined by the applied electric field, Zc is the characteristic impedance of the SWNT which is approximately 12 kΩ, γp is the plasmon propogation constant, and l is the length of the tube which we take to be 1 μm. We estimate a field enhancement factor of approximately 106in the near field given by:
F=ωl(LC/2)1/2/(k2r2)
where L is the kinetic inductance of the SWNT, C is the total capacitance including both electrostatic and quantum capacitances, r is the radial distance between the SWNT axis and the REI, and k and ω are the wavevector and frequency of the incoming light, respectively.
The electromagnetic fields will be calculated using the electric Hertz potential satisfying the Helmholtz equation with proper boundary conditions. The conductivity of the SWNT antenna in the transmission line model is given by:
σ=iωL-1/(ω2+iωL-1R-C-1L-1 γp
2)
where R is the resistance of the SWNT.
The interaction of these calculated plasmonic fields with the REI will modulate the lifetimes of the REI. The modulated lifetimes of an electric dipole emitter will be calculated to model the allowed optical transitions of the particular REI. To include the modulations of the optically dark REI transitions, a magnetic dipole emitter will be used.
To conclude, these results will give a better understanding of the near field electromagnetic interactions that take place in complexes containing SWNTs and REIs and allow for more efficient sensors.

Acknowledgement: This work was supported by: NSF ECCS-1202398

References:

[1] T. Ignatova, H.Najafov, A. Ryasnyanskiy, I. Biaggio, M. Zheng, and SV. Rotkin, “Significant FRET between SWNT/DNA and Rare Earth Ions: A Signature of Their Spatial Correlations”, ACS Nano 2011 5 (7), 6052-6059
[2] PJ. Burke, S. Li, Z.Yu, "Quantitative theory of nanowire and nanotube antenna performance," IEEE Transactions on Nanotechnology 2006 5 (4), 314-334.