Encrypted login | home

Program Information

Development of a System for Magnetic Relaxometry Studies of Magnetic Nanoparticles

O Baffa

O Baffa1*, S Arsalani1 , E Vidoto2 , A Tannus2 , (1) Universidade de Sao Paulo, Ribeirao Preto, SP, (2) Universidade de Sao Paulo, Sao Carlos, SP,


WE-RAM1-GePD-I-1 (Wednesday, August 2, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Lounge

Purpose: Develop a system based on optically pumped magnetometers to measure the Néel relaxation in magnetic nanoparticles (MNPs).

Methods: After magnetic nanoparticles are oriented in a magnetic field they tend to relax by Brownian and Néel relaxation mechanisms. When the particles are attached to cells, Brownian relaxation is minimized and the Néel relaxation is dominant. Thus, this method has a great ability to measure cells that have been target with functionalized MNPs. A short magnetic field pulse is applied and the remanent magnetization is measured with an optically pumped magnetometer.

Results: A self-shielded magnetizing coil was calculated using the simulating annealing technique. Measurements of the calculated specs were done giving: Efficiency calculated -3.83 10⁻⁴ T per ampere. Electrical resistance of 1.44 Ω. @ 25 C. ΔT=10 C after 10 minutes with 50W. Inductance 290 μH. Residual field in a concentric cylindrical shell with 75mm of radius better than 1.43% of the central field. A circuit to switch the current on and off was designed and tested.

Conclusion: The specs projected for the magnetizing coil were attained and the next step is to assembly the coil and OPM to assess the system sensitivity it is expected that the system sensitivity should be sufficient to measure clinically significant concentrations of cells target with MNPs. Funding Support: FAPESP- 2016/06032-0 CNPq

Contact Email: