Publications
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Charge transfer in steam purified arc discharge single walled carbon nanotubes filled with lutetium halides
Santidrián A., Kierkowicz M., Pach E., Darvasiová D., Ballesteros B., Tobias G., Kalbáč M. Physical Chemistry Chemical Physics; 22 (18): 10063 - 10075. 2020. 10.1039/d0cp01408g. IF: 3.430
In the present work, the effect of doping on electronic properties in bulk purified and filled arc-discharge single-walled carbon nanotubes samples is studied for the first time by in situ Raman spectroelectrochemical method. A major challenge to turn the potential of SWCNTs into customer applications is to reduce or eliminate their contaminants by means of purification techniques. Besides, the endohedral functionalization of SWCNTs with organic and inorganic materials (i.e. metal halides) allows the development of tailored functional hybrids. Here, we report the purification and endohedral functionalization of SWCNTs with doping affecting the SWCNTs. Steam-purified SWCNTs have been filled with selected lutetium(iii) halides, LuCl3, LuBr3, LuI3, and sealed using high-temperature treatment, yielding closed-ended SWCNTs with the filling material confined in the inner cavity. The purified SWCNTs were studied using TGA, EDX, STEM and Raman spectroscopy. The lutetium(iii) halide-filled SWCNTs (LuX3@SWCNTs) were characterized using STEM, EDX, Raman spectroscopy and in situ Raman spectroelectrochemistry. It was found that there is a charge transfer between the SWCNTs and the encapsulated LuX3 (X = Cl, Br, I). The obtained data testify to the acceptor doping effect of lutetium(iii) halides incorporated into the SWCNT channels, which is accompanied by the charge transfer from nanotube walls to the introduced substances. © 2020 the Owner Societies.
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Differential properties and effects of fluorescent carbon nanoparticles towards intestinal theranostics
Vallan L., Hernández-Ferrer J., Grasa L., González-Domínguez J.M., Martínez M.T., Ballesteros B., Urriolabeitia E.P., Ansón-Casaos A., Benito A.M., Maser W.K. Colloids and Surfaces B: Biointerfaces; 185 (110612) 2020. 10.1016/j.colsurfb.2019.110612. IF: 4.389
Given the potential applications of fluorescent carbon nanoparticles in biomedicine, the relationship between their chemical structure, optical properties and biocompatibility has to be investigated in detail. In this work, different types of fluorescent carbon nanoparticles are synthesized by acid treatment, sonochemical treatment, electrochemical cleavage and polycondensation. The particle size ranges from 1 to 6 nm, depending on the synthesis method. Nanoparticles that were prepared by acid or sonochemical treatments from graphite keep a crystalline core and can be classified as graphene quantum dots. The electrochemically produced nanoparticles do not clearly show the graphene core, but it is made of heterogeneous aromatic structures with limited size. The polycondensation nanoparticles do not have C[dbnd]C double bonds. The type of functional groups on the carbon backbone and the optical properties, both absorbance and photoluminescence, strongly depend on the nanoparticle origin. The selected types of nanoparticles are compatible with human intestinal cells, while three of them also show activity against colon cancer cells. The widely different properties of the nanoparticle types need to be considered for their use as diagnosis markers and therapeutic vehicles, specifically in the digestive system. © 2019 Elsevier B.V.
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Large thermoelectric power variations in epitaxial thin films of layered perovskite GdBaCo2O5.5±δwith a different preferred orientation and strain
Chatterjee A., Chavez-Angel E., Ballesteros B., Caicedo J.M., Padilla-Pantoja J., Leborán V., Sotomayor Torres C.M., Rivadulla F., Santiso J. Journal of Materials Chemistry A; 8 (38): 19975 - 19983. 2020. 10.1039/d0ta04781c. IF: 11.301
This work describes the growth of thin epitaxial films of the layered perovskite material GdBaCo2O5.5±δ(GBCO) on different single crystal substrates SrTiO3(STO), (LaAlO3)0.3(Sr2TaAlO6)0.7(LSAT) and LaAlO3(LAO) as an approach to study changes in the thermoelectric properties by means of the induced epitaxial strain. In addition to strain changes, the films grow with considerably different preferred orientations and domain microstructures: GBCO films on STO are purelyc-axis oriented (c⊥) with an average 0.18% in-plane tensile strain; GBCO on LSAT is composed of domains with a mixed orientation (c‖andc⊥) with an average 0.71% in-plane compressive strain; while on LAO it isb-axis oriented (c‖) with an average 0.89% in-plane compressive strain. These differences result in important cell volume changes, as well as in the orthorhombicity of thea-bplane of the GBCO structure, which in turn induce a change in the sign and temperature dependence of the thermopower, while the electrical conductivity remains almost unchanged. In general, compressively strained films show negativeSthermopower (n-type) while tensile strained films show a positiveS(p-type) at low temperatures, probing the adaptive nature of the GdBaCo2O5.5±δcompound. These results point to the spontaneous generation of oxygen vacancies to partially accommodate the epitaxial stress as the main cause for this effect. © The Royal Society of Chemistry 2020.
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Multi-approach analysis to assess the chromium(III) immobilization by Ochrobactrum anthropi DE2010
Villagrasa E., Ballesteros B., Obiol A., Millach L., Esteve I., Solé A. Chemosphere; 238 (124663) 2020. 10.1016/j.chemosphere.2019.124663. IF: 5.778
Ochrobactrum anthropi DE2010 is a microorganism isolated from Ebro Delta microbial mats and able to resist high doses of chromium(III) due to its capacity to tolerate, absorb and accumulate this metal. The effect of this pollutant on O. anthropi DE2010 has been studied assessing changes in viability and biomass, sorption yields and removal efficiencies. Furthermore, and for the first time, its capacity for immobilizing Cr(III) from culture media was tested by a combination of High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM) imaging coupled to Energy Dispersive X-ray spectroscopy (EDX). The results showed that O. anthropi DE2010 was grown optimally at 0–2 mM Cr(III). On the other hand, from 2 to 10 mM Cr(III) microbial plate counts, growth rates, cell viability, and biomass decreased while extracellular polymeric substances (EPS) production increases. Furthermore, this bacterium had a great ability to remove Cr(III) at 10 mM (q = 950.00 mg g−1) immobilizing it mostly in bright polyphosphate inclusions and secondarily on the cellular surface at the EPS level. Based on these results, O. anthropi DE2010 could be considered as a potential agent for bioremediation in Cr(III) contaminated environments. © 2019 Elsevier Ltd
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Neutron Activated 153Sm Sealed in Carbon Nanocapsules for in Vivo Imaging and Tumor Radiotherapy
Wang J.T.-W., Klippstein R., Martincic M., Pach E., Feldman R., Šefl M., Michel Y., Asker D., Sosabowski J.K., Kalbac M., Da Ros T., Ménard-Moyon C., Bianco A., Kyriakou I., Emfietzoglou D., Saccavini J.-C., Ballesteros B., Al-Jamal K.T., Tobias G. ACS Nano; 14 (1): 129 - 141. 2020. 10.1021/acsnano.9b04898. IF: 14.588
Radiation therapy along with chemotherapy and surgery remain the main cancer treatments. Radiotherapy can be applied to patients externally (external beam radiotherapy) or internally (brachytherapy and radioisotope therapy). Previously, nanoencapsulation of radioactive crystals within carbon nanotubes, followed by end-closing, resulted in the formation of nanocapsules that allowed ultrasensitive imaging in healthy mice. Herein we report on the preparation of nanocapsules initially sealing "cold" isotopically enriched samarium (152Sm), which can then be activated on demand to their "hot" radioactive form (153Sm) by neutron irradiation. The use of "cold" isotopes avoids the need for radioactive facilities during the preparation of the nanocapsules, reduces radiation exposure to personnel, prevents the generation of nuclear waste, and evades the time constraints imposed by the decay of radionuclides. A very high specific radioactivity is achieved by neutron irradiation (up to 11.37 GBq/mg), making the "hot" nanocapsules useful not only for in vivo imaging but also therapeutically effective against lung cancer metastases after intravenous injection. The high in vivo stability of the radioactive payload, selective toxicity to cancerous tissues, and the elegant preparation method offer a paradigm for application of nanomaterials in radiotherapy. Copyright © 2019 American Chemical Society.
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Neutron-irradiated antibody-functionalised carbon nanocapsules for targeted cancer radiotherapy
Wang J.T.-W., Spinato C., Klippstein R., Costa P.M., Martincic M., Pach E., Ruiz de Garibay A.P., Ménard-Moyon C., Feldman R., Michel Y., Šefl M., Kyriakou I., Emfietzoglou D., Saccavini J.-C., Ballesteros B., Tobias G., Bianco A., Al-Jamal K.T. Carbon; 162: 410 - 422. 2020. 10.1016/j.carbon.2020.02.060. IF: 8.821
Radiotherapy is a cancer treatment utilising high doses of ionizing radiation to destroy cancer cells. Our team has pioneered neutron activation of 152Sm, filled and sealed into single-walled (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), to create stable and high-dose radioactive carbon nanocapsules for cancer radiotherapy. In this work, MWCNTs filled with enriched 152SmCl3 (Sm@MWCNTs) were sealed and irradiated, followed by surface functionalisation with an epidermal growth factor receptor (EGFR)-targeting antibody. Characterisation of functionalised Sm@MWCNTs was carried out using thermogravimetric analysis, gel electrophoresis and transmission electron microscopy. The organ biodistribution of the radioactive functionalised 153Sm@MWCNTs and therapeutic efficacy were studied in an experimental melanoma lung metastatic tumour model in mice after intravenous injection. Quantitative biodistribution analyses showed high accumulation of 153Sm@MWCNT-Ab in lung. Significant tumour growth reduction was induced by both treatments of 153Sm@MWCNTs functionalised with or without the antibody after a single intravenous injection. Although EGFR targeting showed no improvement in therapeutic efficacy, reduced spleen toxicity and normal haematological profiles were obtained for both functionalised derivatives. The current study demonstrated the possibility of performing chemical functionalisation and antibody conjugation on radioactive nanocapsules post-irradiation for the preparation of targeted radiopharmaceuticals. © 2020 Elsevier Ltd
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P-Type Ultrawide-Band-Gap Spinel ZnGa2O4: New Perspectives for Energy Electronics
Chikoidze E., Sartel C., Madaci I., Mohamed H., Vilar C., Ballesteros B., Belarre F., Del Corro E., Vales-Castro P., Sauthier G., Li L., Jennings M., Sallet V., Dumont Y., Pérez-Tomás A. Crystal Growth and Design; 20 (4): 2535 - 2546. 2020. 10.1021/acs.cgd.9b01669. IF: 4.089
The family of spinel compounds is a large and important class of multifunctional materials of general formulation AB2X4 with many advanced applications in energy and optoelectronic areas such as fuel cells, batteries, catalysis, photonics, spintronics, and thermoelectricity. In this work, it is demonstrated that the ternary ultrawide-band-gap (∼5 eV) spinel zinc gallate (ZnGa2O4) arguably is the native p-type ternary oxide semiconductor with the largest Eg value (in comparison with the recently discovered binary p-type monoclinic β-Ga2O3 oxide). For nominally undoped ZnGa2O4 the high-temperature Hall effect hole concentration was determined to be as large as p = 2 × 1015 cm-3, while hole mobilities were found to be μh = 7-10 cm2/(V s) (in the 680-850 K temperature range). An acceptor-like small Fermi level was further corroborated by X-ray spectroscopy and by density functional theory calculations. Our findings, as an important step toward p-type doping, opens up further perspectives for ultrawide-band-gap bipolar spinel electronics and further promotes ultrawide-band-gap ternary oxides such as ZnGa2O4 to the forefront of the quest of the next generation of semiconductor materials for more efficient energy optoelectronics and power electronics. Copyright © 2020 American Chemical Society.
