Rod-shaped nanostructures based on superparamagnetic nanocrystals as viscosity sensors in liquid

The following article appeared in Journal of Applied Physics 110.6 (2011): 064907 and may be found at http://scitation.aip.org/content/aip/journal/jap/110/6/10.1063/1.3638695
Superparamagnetic nanostructures are becoming increasingly important as tools for biological and medical applications. We report the study of the movement of rod-shaped assemblies of superparamagnetic nanocrystals under the action of a rotating magnetic field. The dynamic was characterized by means of light scattering detection at different frequencies and for different values of the intensity of the applied external field. The possibility to correlate the motion to the viscosity of the medium is used to monitor viscosity changes inside the liquid. We propose this technique as a valuable tool to monitor viscosity at microscale for application in biological studies.
This work was partially supported by the European project Magnifyco (Contract NMP4-SL-2009-228622).