Detection of magnetic nanoparticles utilizing cooled normal pickup coil and high Tc SQUID

Magnetic nanoparticles coupled with medicine or reagents have been studied for the application to in vivo medical diagnosis and drug delivery. For these applications, we have been developing a measurement system to detect the position and amount of the magnetic nanoparticles accumulated inside the body by using a cooled Copper pickup coil and high T-c SQUID. The susceptibility measurement method with an excitation filed is used to detect the magnetic nanoparticles. Experimental results, such as contour map of the signal field and the distance-dependence of the detected signal, are shown. At present, we could detect 50 mu g of Fe3O4 particles that are located below the pickup coil at the distance of 30 mm. (C) 2009 Elsevier B.V. All rights reserved.