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Author Chowdhury, M.S.; Rösch, E.L.; Esteban, D.A.; Janssen, K.-J.; Wolgast, F.; Ludwig, F.; Schilling, M.; Bals, S.; Viereck, T.; Lak, A. url  doi
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  Title Decoupling the Characteristics of Magnetic Nanoparticles for Ultrahigh Sensitivity Type A1 Journal article
  Year (down) 2023 Publication Nano letters Abbreviated Journal  
  Volume 23 Issue 1 Pages 58-65  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Immunoassays exploiting magnetization dynamics of magnetic nanoparticles are highly promising for mix-and-measure, quantitative, and point-of-care diagnostics. However, how single-core magnetic nanoparticles can be employed to reduce particle concentration and concomitantly maximize assay sensitivity is not fully understood. Here, we design monodisperse Néel and Brownian relaxing magnetic nanocubes (MNCs) of different sizes and compositions. We provide insights into how to decouple physical properties of these MNCs to achieve ultrahigh sensitivity. We find that tri-component-based Zn0.06 Co0.80Fe2.14 O4 particles, with out-of-phase to initial magnetic susceptibility χ /χ ratio of 0.47 out of 0.50 for magnetically blocked ideal particles, show the ultrahigh magnetic sensitivity by providing rich magnetic particle spectroscopy (MPS) harmonics spectrum despite bearing lower saturation magnetization than di-component Zn0.1Fe2.9O4 having high saturation magnetization. The Zn0.06Co0.80Fe2.14O4 MNCs, coated with catechol-based polyethylene glycol ligands, measured by our benchtop MPS show three orders of magnitude better particle LOD than that of commercial nanoparticles of comparable size.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000907816300001 Publication Date 2023-01-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.8 Times cited 1 Open Access OpenAccess  
  Notes Deutsche Forschungsgemeinschaft, DFG RTG 1952 ; Joachim Herz Stiftung; H2020 Research Infrastructures, 823717 ; Approved Most recent IF: 10.8; 2023 IF: 12.712  
  Call Number EMAT @ emat @c:irua:193406 Serial 7248  
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Author Lak, A.; Cassani, M.; Mai, B.T.; Winckelmans, N.; Cabrera, D.; Sadrollahi, E.; Marras, S.; Remmer, H.; Fiorito, S.; Cremades-Jimeno, L.; Litterst, F.J.; Ludwig, F.; Manna, L.; Teran, F.J.; Bals, S.; Pellegrino, T. pdf  url
doi  openurl
  Title Fe2+Deficiencies, FeO Subdomains, and Structural Defects Favor Magnetic Hyperthermia Performance of Iron Oxide Nanocubes into Intracellular Environment Type A1 Journal article
  Year (down) 2018 Publication Nano letters Abbreviated Journal Nano Lett  
  Volume 18 Issue 18 Pages 6856-6866  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Herein, by studying a stepwise phase transformation of 23 nm FeO-Fe3O4 core-shell nanocubes into Fe3O4, we identify a composition at which the magnetic heating performance of the nanocubes is not affected by the medium viscosity and aggregation. Structural and magnetic characterizations reveal the transformation of the FeO-Fe3O4 nanocubes from having stoichiometric phase compositions into Fe2+ deficient Fe3O4 phases. The resultant nanocubes contain tiny compressed and randomly distributed FeO sub-domains as well as structural defects. This phase transformation causes a tenfold increase in the magnetic losses of the nanocubes, which remains exceptionally insensitive to the medium viscosity as well as aggregation unlike similarly sized single-phase magnetite nanocubes. We observe that the dominant relaxation mechanism switches from Néel in fresh core-shell nanocubes to Brownian in partially oxidized nanocubes and once again to Néel in completely treated nanocubes. The Fe2+ deficiencies and structural defects appear to reduce the magnetic energy barrier and anisotropy field, thereby driving the overall relaxation into Néel process. The magnetic losses of the particles remain unchanged through a progressive internalization/association to ovarian cancer cells. Moreover, the particles induce a significant cell death after being exposed to hyperthermia treatment. Here, we present the largest heating performance that has been reported to date for 23 nm iron oxide nanoparticles under cellular and intracellular conditions. Our findings clearly demonstrate the positive impacts of the Fe2+ deficiencies and structural defects in the Fe3O4 structure on the heating performance under cellular and intracellular conditions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000451102100028 Publication Date 2018-11-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.712 Times cited 51 Open Access OpenAccess  
  Notes This work is partially funded by the European Research Council (starting grant ICARO, Contract No. 678109 and COLOURATOM-335078), Spanish Ministry of Economy and Competitiveness (MAT2016-81955-REDT, SEV-2016-0686, MAT2017-85617-R) Comunidad de Madrid (NANOFRONTMAG-CM, S2013/MIT-2850), the European COST Action TD1402 (RADIOMAG), and Ramon y Cajal subprogram (RYC-2011-09617). Financial support from the Deutsche Forschungsgemeinschaft, DFG Priority Program 1681 (LU800/4-3). S.B. and N.W. acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through Project funding G038116N. A.L. acknowledges the Alexander von Humboldt Foundation for the Postdoctoral Research Fellow funding. Mr Emilio J. Artés from the Advanced Instrumentation Unit (iMdea Nanociencia) is acknowledged for his technical assistance. L. M acknowledges the predoctoral fellowship funded from Comunidad de Madrid (PEJD-2017-PRE/IND-4189). Authors thank Tiziano Catelani and Doriana Debellis for the preparation of TEM cell samples (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ecas_Sara Approved Most recent IF: 12.712  
  Call Number EMAT @ emat @c:irua:155439UA @ admin @ c:irua:155439 Serial 5072  
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Author Schrittwieser, S.; Pelaz, B.; Parak, W.J.; Lentijo-Mozo, S.; Soulantica, K.; Dieckhoff, J.; Ludwig, F.; Altantzis, T.; Bals, S.; Schotter, J. pdf  url
doi  openurl
  Title Homogeneous Protein Analysis by Magnetic Core-Shell Nanorod Probes Type A1 Journal article
  Year (down) 2016 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter  
  Volume 8 Issue 8 Pages 8893-8899  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Studying protein interactions is of vital importance both to fundamental biology research and to medical applications. Here, we report on the experimental proof of a universally applicable label-free homogeneous platform for rapid protein analysis. It is based on optically detecting changes in the rotational dynamics of magnetically agitated core-shell nanorods upon their specific interaction with proteins. By adjusting the excitation frequency, we are able to optimize the measurement signal for each analyte protein size. In addition, due to the locking of the optical signal to the magnetic excitation frequency, background signals are suppressed, thus allowing exclusive studies of processes at the nanoprobe surface only. We study target proteins (soluble domain of the human epidermal growth factor receptor 2 – sHER2) specifically binding to antibodies (trastuzumab) immobilized on the surface of our nanoprobes and demonstrate direct deduction of their respective sizes. Additionally, we examine the dependence of our measurement signal on the concentration of the analyte protein, and deduce a minimally detectable sHER2 concentration of 440 pM. For our homogeneous measurement platform, good dispersion stability of the applied nanoprobes under physiological conditions is of vital importance. To that end, we support our measurement data by theoretical modeling of the total particle-particle interaction energies. The successful implementation of our platform offers scope for applications in biomarker-based diagnostics as well as for answering basic biology questions.  
  Address Molecular Diagnostics, AIT Austrian Institute of Technology , Vienna, Austria  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language English Wos 000374274900007 Publication Date 2016-03-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.504 Times cited 16 Open Access OpenAccess  
  Notes The authors thank Frauke Alves, Julia Bode and Fernanda Ramos Gomes from the Max-Planck-Institute of Experimental Medicine in Göttingen for providing the trastuzumab antibody in form of the Herceptin therapeutic drug. The figure showing the measurement principle has been created by Darragh Crotty (www.darraghcrotty.com). Parts of this research were supported by the European Commission FP7 NAMDIATREAM project (EU NMP4-LA-2010−246479), by the German research foundation (DFG grant GRK 1782 to W.J.P.), and by the European Research Council (ERC Starting Grant #335078 Colouratom). B.P. acknowledges a PostDoctoral fellowship from the Alexander von Humboldt foundation. (ROMEO:white; preprint:; postprint:restricted 12 months embargo; pdfversion:cannot); ; ECAS_Sara; Approved Most recent IF: 7.504  
  Call Number c:irua:132889 Serial 4059  
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