Poster Dealing with the application magnetoimpeditive Co-based ribbons for magnetic marker detection.

1. Phisiologicaly stable magnetic nanoparticles
and magnetoimpedance sensor
Universidad de Oviedo
D. Lago*, M. Rivas, J.C. Martínez-García, J.A. García
Dpto. de Física, Universidad de Oviedo, Calvo Sotelo s/n, 33007 Oviedo, Spain
* Edificio Departamental Este, Campus de Viesques, 33204 Gijón, Spain e-mail: lagodavid@uniovi.es
The aim of this Project is in vitro labeling, magnetic detection and separation of tumor cells. Magnetite nanoparticles or functionalized nickel na-
nowires are bound to the specific antibody against the surface protein of the tumor. The nanoestructures are then detected by a magnetic biosensor
[1]
based on the Giant MagnetoImpedance (GMI) effect of an Co-based amorphous metallic ribbon . Similar nanoparticles have been detected embed-
[2] [3]
ded inside human embryonic kidney cells , and the use of antibody-functionalized nanowires for cell separation has also been studied , showing low
citotoxicity without any biocompatible coating.
Functionalized
nanoparticle with Nanoparticles’
Fe3O4
nanoparticle Specific Antibody Magnetic Field
Tumor Cell
Fe3O4@SiO2
nanoparticle Detection System
Nanowires’
Magnetic Field
Ribbon
with
GMI
Tumor Cell
Ni Nanowire Functionalized
Nanowire with
We have produced Co70Fe5Si15B10 by melt-spinning which in as-quenched state presents large GMI that allows the detection of nanowires.
Detection
Detection
No detection
After annealing and Measuring with
premagnetization H=0
GMI curves of as-quenched ribbon showing the GMI curves of premagnetized ribbon impedan- Nanowires detection with annealed and premag-
effect of nanowires. ce showing the effect of nanowires. netized ribbon with no applied field.
In a first step we produced 10 nm diameter iron oxide nanoparticles, with narrow size distribu-
Fe3O4 d~10nm
tion. Secondly, the nanoparticles were covered with a biocompatible silica surface coating, con-
Fe3O4@SiO2 d~20nm
serving the spherical form, the superparamagnetic behaviour and the narrow size distribution, as
Fe3O4@SiO2 d~40nm shown in the transmision electron micrography of nanoparticles. The thicker the silica coating, the
weaker the magnetic field which can be detected. Hysteresis loops of the naked magnetite nano-
particles, nanoparticles covered with 5 nm silica (20 nm total diameter of nanoparticle), and nano-
particles with 10 nm silica (40 nm total diameter) were measured using a SQUID. Finally, the nano-
particles were conjugated to the specific targeting ligands.
References
1. J.C. Martínez-García, M. Rivas, L. Elbaile, R. Díaz-Crespo, J.A. García and S. Volchkov; Sens. Lett. 7 (2009) p. 497.
2. A. Kumar, S. Mohapatra, V. Fal-Miyar, A. Cerdeira, J.A. García, H. Srikanthy, J. Gass and G.V. Kurlyandskaya; Appl. Phys. Lett. 91 (2007) p. 143902.
3. N Gao, H. Wang, and E-H. Yang; Nanotechnology 21 (2010) p. 105107.
This project is done in collaboration with Nanogap and financed under grant IB09-128 by the Government of the Principality of Asturias