abstract
Magnetic nanoparticles are widely explored in bio-related applications, as sensing probes, as local heat generators, and as contrast agents for imaging. The large majority of these nanoparticles are iron oxides and cubic ferrites with low to medium magnetic anisotropy, and thus a weak to medium coupling between spins and crystal lattice. Here we present stable aqueous colloidal suspensions made of a doped iron oxide (Al-doped epsilon-Fe2O3) with a strong coupling between the magnetic moment and the crystal lattice. We show that in stable aqueous suspensions, these highly anisotropic nanoparticles are cell-compatible and follow a rigid dipole model, enabling viscosity sensing, and viscosity imaging using a magnetic particle imaging (MPI) scanner. This opens new perspectives for bio-application of magnetic nanoparticles, such as 3D viscosity imaging with sub-second resolution using MPI, a tomographic technique with kHz imaging rates.
keywords
GIANT COERCIVE FIELD; WAVE ABSORBER
subject category
Science & Technology - Other Topics; Materials Science; Physics
authors
Costa, JM; Resende, GF; Gu, Y; Fernandes, SP; Silvares, JNM; Lagarto, MR; Sousa, FL; Gaspar, VM; Mano, J; Millán, A; Garcia-Palacios, JL; Vogel, P; Namai, A; Yoshikiyo, M; Ohkoshi, S; Silva, NJO
our authors
Filipa Lourosa Sousa
Junior Researcher
João Mano
Full professor
Nuno João Silva
Principal Researcher
Vítor Gaspar
Assistant ProfessorGroups
G2 - Photonic, Electronic and Magnetic Materials
G5 - Biomimetic, Biological and Living Materials
Projects
Development of 4D wireless thermometry to target tumor ablation (PTDC/NAN-MAT/3901/2020)
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
3D temperature mapping critical to understanding the nanoworld (ThermoRise)
acknowledgements
The authors thank Hitachi for providing the STEM images. This work was supported by Grants PTDC/NAN-MAT/3901/2020 (supported by POCI, FEDER and FCT/MCTES) and CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 and LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). These results are part of project ThermoRise that has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant agreement No. ERC-2019-CoG-865437). S P F acknowledges a STSM grant from COST Action CA23132 NexMPI. G.F.R. was supported by FCT-Fundacao para a Ciencia e Tecnologia, I.P. by project reference 2023.01044.BD and DOI identifier https://doi.org/10.54499/2023.01044.BD.Detailed experimental procedures, characterization data, rigid dipole model implementation, a video of the transparent ferrofluid under an external field, and a video of the mz vs. eta dependence for increasing f are available.