The Scale of FePt Nanoparticles Metrology Needs for Magnetic Nanoparticles How to Measure the Magnetic Properties of Individual Particles? David E. Nikles Department of Chemistry and Center for Materials for Information Technology The University of Alabama, Tuscaloosa, Alabama 35487-0209 The Scale of FePt Nanoparticles A 3.5 nm FePt particle Volume 22 nm3 or 2.2 x 10-20 cm3 About 816 Fe atoms and 816 Pt atoms Mass 3.4 x 10-19 g Magnetization 2.5 x 10-17 emu Self-assembled FePt nanoparticles

Biomedical Applications of Magnetic Nanoparticles Bead Array Counter (BARC) BARC Biosensor Chip for the multi-analyte assay of biomolecules Uses DNA hybridization GMR sensing Magnetic bead labeling Detection of biowarfare agents Illustration courtesy of D. T. Johnson, Department of Chemical Engineering, University of Alabama