Controlled torque on superparamagnetic beads for functional biosensors.

We demonstrate that a rotating magnetic field can be used to apply a controlled torque on superparamagnetic beads which leads to a tunable bead rotation frequency in fluid. Smooth rotation is obtained for field rotation frequencies many orders of magnitude higher than the bead rotation frequency. A quantitative model is developed, based on results from a comprehensive set of experiments at different field strengths and frequencies. At low frequencies (<10Hz), rotation is due to a small permanent magnetic moment in the bead. At high frequencies (kHz-MHz), the torque results from a phase lag between the applied field and the induced magnetic moment, caused by the non-zero relaxation time of magnetic nanoparticles in the bead. The control of torque and rotation will enable novel functional assays in bead-based biosensors.

[1]  D. Wild.  The Immunoassay Handbook , 2001 .

[2]  A. T. Giannitsis,et al.  Investigation of the complex susceptibility of magnetic beads containing maghemite nanoparticles , 2006 .

[3]  Sensitive bondforce measurements of ligand-receptor pairs with magnetic beads. , 2005, Biosensors & bioelectronics.

[4]  G. Fonnum,et al.  Characterisation of Dynabeads® by magnetization measurements and Mössbauer spectroscopy , 2005 .

[5]  S. Linderoth,et al.  Surface effects in metallic iron nanoparticles. , 1994, Physical review letters.

[6]  Galina V. Kurlyandskaya,et al.  Giant-magnetoimpedance-based sensitive element as a model for biosensors , 2003 .

[7]  K. Besteman,et al.  Role of tension and twist in single-molecule DNA condensation. , 2007, Physical review letters.

[8]  Paul E. Sheehan,et al.  Design and Performance of GMR Sensors for the Detection of Magnetic Microbeads in Biosensors , 2003 .

[9]  É. Duguet,et al.  Magnetic nanoparticle design for medical diagnosis and therapy , 2004 .

[10]  M. Prins,et al.  On-chip manipulation and detection of magnetic particles for functional biosensors. , 2008, Biosensors & bioelectronics.

[11]  Gustaaf Borghs,et al.  Single magnetic particle detection: Experimental verification of simulated behavior , 2006 .

[12]  M. S. Pedersen,et al.  Magnetic properties of magnetic liquids with iron-oxide particles — The influence of anisotropy and interactions , 1997 .

[13]  T. Morozova,et al.  Force differentiation in recognition of cross-reactive antigens by magnetic beads. , 2008, Analytical biochemistry.

[14]  Daniel A. Koster,et al.  Antitumour drugs impede DNA uncoiling by topoisomerase I , 2007, Nature.

[15]  M. Megens,et al.  Scanning probe measurements on a magnetic bead biosensor , 2007 .

[16]  K. Knížek,et al.  New Tc-tuned magnetic nanoparticles for self-controlled hyperthermia , 2007 .

[17]  L. Whitman,et al.  Rapid, femtomolar bioassays in complex matrices combining microfluidics and magnetoelectronics. , 2007, Biosensors & bioelectronics.

[18]  Hugo Ferreira,et al.  Planar Hall effect sensor for magnetic micro- and nanobead detection , 2004 .

[19]  V. Pott,et al.  Detection of a single magnetic microbead using a miniaturized silicon Hall sensor , 2002 .

[20]  Gil U. Lee,et al.  A biosensor based on magnetoresistance technology. , 1998, Biosensors & bioelectronics.

[21]  C. Chien,et al.  Controllable high-speed rotation of nanowires , 2005, cond-mat/0503162.

[22]  Petr I. Nikitin,et al.  New type of biosensor based on magnetic nanoparticle detection , 2007 .

[23]  Hugo Ferreira,et al.  Magnetic microbead detection using the planar Hall effect , 2005 .

[24]  F Thalmann,et al.  Measuring the kinetics of biomolecular recognition with magnetic colloids. , 2008, Physical review letters.

[25]  Andrea Prieto Astalan,et al.  Biomolecular reactions studied using changes in Brownian rotation dynamics of magnetic particles. , 2004, Biosensors & bioelectronics.

[26]  B. M. de Boer,et al.  An integrated and sensitive detection platform for magneto-resistive biosensors. , 2007, Biosensors & bioelectronics.

[27]  J. H. Nieuwenhuis,et al.  Confined Brownian motion of individual magnetic nanoparticles on a chip: Characterization of magnetic susceptibility , 2006 .

[28]  B. Boser,et al.  A novel magnetic bead bioassay platform using a microchip-based sensor for infectious disease diagnosis. , 2006, Journal of immunological methods.