Spatial Resolution in Micrometric Periodic Assemblies of Magnetotactic Bacteria and Magnetic Nanoparticles

A. J. MORENO, E. GONZALEZ, M. GODOY, J. PETTINARI, P.S.ANTONEL, G. JORGE AND V. BEKERIS

IEEE TRANSACTIONS ON MAGNETICS

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

Lugar: New York; Año: 2013

0018-9464

Abstract— The improvement of different methods for manipulation of nano and micro arrangements of magnetic nanoparticles is an area of intense research. Particle assemblies may be employed in scientific and technical fields like spintronics, magnetic memory devices and in healthcare. We developed a simple method for obtaining micro arrays of magnetic nanoparticles using audio tapes. We present spatial micro-arrangements of magnetotactic bacteria (Magnetospirillum gryphiswaldense), magnetite (Fe3O4) and functionalized cobalt ferrite (CoFe2O4) nanoparticles. Computer generated square audio waves of different frequencies (100 Hz – 10 kHz) were recorded leading to magnetic patterns of different micrometer spatial wavelengths. Drops of aqueous solutions were deposited on the tapes as described below to control particle density, and bacteria and particles were trapped at locations where magnetic energy is minimized, as observed using conventional optical microscopy after the solvent was evaporated. We discuss the spatial limits of the magnetic nanoparticles and the bacteria assemblies, concluding that cell walls of bacteria inhibit agglomeration and optimize spatial organization.