Modifying the magnetic response of magnetotactic bacteria incorporation of Gd and Tb ions into the magnetosome structure
| العنوان: | Modifying the magnetic response of magnetotactic bacteria incorporation of Gd and Tb ions into the magnetosome structure |
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| المؤلفون: | E. M. Jefremovas, L. Gandarias, L. Marcano, A. Gacía-Prieto, I. Orue, A. Muela, M. L. Fdez-Gubieda, L. Fernández Barquín, J. Alonso |
| المساهمون: | Universidad de Cantabria |
| المصدر: | Nanoscale Advances, 2022, 4, 2649-(CORRIGENDUM), 2022, 4, 2762 Addi. Archivo Digital para la Docencia y la Investigación instname |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | hyperthermia treatment, growth, General Engineering, agent, Bioengineering, anisotropy, General Chemistry, Atomic and Molecular Physics, and Optics, verwey transition, chains, Others, nanoparticles, General Materials Science |
| الوصف: | Magnetotactic bacteria Magnetospirillum gryphiswaldense MSR-1 biosynthesise chains of cube-octahedral magnetosomes, which are 40 nm magnetite high quality (Fe3O4) nanoparticles. The magnetic properties of these crystalline magnetite nanoparticles, which can be modified by the addition of other elements into the magnetosome structure (doping), are of prime interest in a plethora of applications, those related to cancer therapy being some of the most promising ones. Although previous studies have focused on transition metal elements, rare earth (RE) elements are very interesting as doping agents, both from a fundamental point of view (e.g. significant differences in ionic sizes) and for the potential applications, especially in biomedicine (e.g. magnetic resonance imaging and luminescence). In this work, we have investigated the impact of Gd and Tb on the magnetic properties of magnetosomes by using different complementary techniques. X-ray diffraction, transmission electron microscopy, and X-ray absorption near edge spectroscopy analyses have revealed that a small amount of RE ions, similar to 3-4%, incorporate into the Fe3O4 structure as Gd3+ and Tb3+ ions. The experimental magnetic characterisation has shown a clear Verwey transition for the RE-doped bacteria, located at T similar to 100 K, which is slightly below the one corresponding to the undoped ones (106 K). However, we report a decrease in the coercivity and remanence of the RE-doped bacteria. Simulations based on the Stoner-Wohlfarth model have allowed us to associate these changes in the magnetic response with a reduction of the magnetocrystalline (K-C) and, especially, the uniaxial (K-uni) anisotropies below the Verwey transition. In this way, K-uni reaches a value of 23 and 26 kJ m(-3) for the Gd- and Tb-doped bacteria, respectively, whilst a value of 37 kJ m(-3) is obtained for the undoped bacteria. This work was supported in part by the Spanish MCIN/AEI under Projects MAT2017-83631-C3-R and PID2020-115704RB-C33. The work of Elizabeth M. Jefremovas was supported by the "Concepci ' on Arenal Grant" awarded by Gobierno de Cantabria and Universidad de Cantabria. The work of Lourdes Marcano was supported by the Postdoctoral Fellowship from the Basque Government under Grant POS-2019-2-0017. The authors would like to thank "Nanotechnology in translational hyperthermia" (HIPERNANO)-RED2018-102626-T. We thank the ALBA (CLAESS beamline) synchrotron radiation facilities and staff for the allocation of beamtime and assistance during the experiments. |
| وصف الملف: | application/pdf |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::68fb7f22621047a845b9858260ffe380 http://www.helmholtz-berlin.de/pubbin/oai_publication?VT=1&ID=109148 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....68fb7f22621047a845b9858260ffe380 |
| قاعدة البيانات: | OpenAIRE |
| الوصف غير متاح. |