In this study, we explored magnetic nanoparticles translocating through a nanopore in the presence of an inhomogeneous magnetic field. By detecting the ionic current blockade signals with a silicon nitride nanopore, we found that the translocation velocity that is driven by magnetic and hydrodynamic forces on a single magnetic nanoparticle can be accurately determined and is linearly proportional to the magnetization of the magnetic nanoparticle. Thus, we obtained the magneto-susceptibility of an individual nanoparticle and the average susceptibility over one hundred particles within a few minutes.
References
[1]
Koh, I.; Josephson, L. Magnetic nanoparticle sensors. Sensors 2009, 9, 8130–8145.
[2]
Haun, J.B.; Yoon, T.-J.; Lee, H.; Weissleder, R. Magnetic nanoparticle biosensors. Wiley Interdiscip. Rev. Nanomed. Nanobiotechnol. 2010, 2, 291–304.
[3]
Biswal, S.L.; Gast, A.P. Micromixing with linked chains of paramagnetic particles. Anal. Chem. 2004, 76, 6448–6455.
[4]
Sandhu, A.; Kumagai, Y.; Lapicki, A.; Sakamoto, S.; Abe, M.; Handa, H. High efficiency Hall effect micro-biosensor platform for detection of magnetically labeled biomolecules. Biosens. Bioelectron. 2007, 22, 2115–2120.
[5]
Park, S.Y.; Handa, H.; Sandhu, A. Magneto-optical biosensing platform based on light scattering from self-assembled chains of functionalized rotating magnetic beads. Nano Lett. 2010, 10, 446–451.
[6]
Baselt, D.R.; Lee, G.U.; Natesan, M.; Metzger, S.W.; Sheehan, P.E.; Colton, R.J. A biosensor based on magnetoresistance technology. Biosens. Bioelectron. 1998, 13, 731–739.
[7]
Park, S.Y.; Handa, H.; Sandhu, A. Determination of inter-molecular forces by magneto-optical transmittance of molecule-covered superparamagnetic particles in solution. IEEE Trans. Magn. 2010, 46, 1409–1411.
[8]
Wang, J.P. FePt Magnetic nanoparticles and their assembly for future magnetic media. Proc. IEEE 2008, 96, 1847–1863.
[9]
Choi, J.W.; Oh, K.W.; Thomas, J.H.; Heineman, W.R.; Halsall, H.B.; Nevin, J.H.; Helmicki, A.J.; Henderson, H.T.; et al. An integrated microfluidic biochemical detection system for protein analysis with magnetic bead-based sampling capabilities. Lab Chip 2002, 2, 27–30.
[10]
Overbeek, J.T.G.; Wiersema, P.H. Interpretation of Electrophoretic Mobilities. In Electrophoresis: Theory, Methods and Applications; Bier, M., Ed.; Academic Press: New York, NY, USA, 1967; Volume 2, pp. 1–52.
[11]
Deblois, R.W.; Bean, C.P. Counting and Sizing of Submicron Particles by Resistive Pulse Techniques. Rev. Sci. Instrum. 1970, 41, 909–916.
[12]
Pamme, N. Continuous flow separations in microfluidic devices. Lab Chip 2007, 7, 1644–1659.
[13]
H？feli, U.O.; Lobedann, M.A.; Streingroewer, J.; Moore, L.R.; Riffle, J. Optical method for measurement of magnetophoretic mobility of individual magnetic microspheres in defined magnetic field. J. Magn. Magn. Mater. 2005, 293, 224–239.
[14]
Storm, A.J.; Chen, J.H.; Ling, X.S.; Zandbergen, H.W.; Dekker, C. Fabrication of solid-state nanopores with single-nanometre precision. Nat. Mater. 2003, 2, 537–540.
[15]
Krapf, D.; Wu, M.Y.; Smeets, R.M.M.; Zandbergen, H.W.; Dekker, C.; Lemay, S.G. Fabrication and characterization of nanopore-based electrodes with radii down to 2 nm. Nano Lett. 2006, 6, 105–109.
[16]
Kowalczyk, S.W.; Grosberg, A.Y.; Rabin, Y.; Dekker, C. Modeling the conductance and DNA blockade of solid-state nanopores. Nanotechnology 2011, 22, 315101.
[17]
Wu, M.Y.; Smeets, R.M.M.; Zandbergen, M.; Ziese, U.; Krapf, D.; Batson, P.E.; Dekker, N.H.; Dekker, C.; Zandbergen, H.W. Control of shape and material composition of solid-state nanopores. Nano Lett. 2009, 9, 479–484.
[18]
CRC Handbook of Chemistry and Physics, 91st ed.; Haynes, W.M., Ed.; CRC Press: Boca Raton, FL, USA, 2010.
[19]
Ito, T.; Sun, L.; Crooks, R.M. Simultaneous determination of the size and surface charge of individual nanoparticles using a carbon nanotube-based coulter counter. Anal. Chem. 2003, 75, 2399–2406.
