Model for Label-Free Detection of Viruses inside Ferrofluid

The authors introduced a novel method for detecting nonmagnetic objects inside ferrofluid as a new method for label-free sensing of whole viruses. The proposed idea is advantageous because it not only avoids the use of labels, but it also permits direct volume measurement of the material attached to the sensor. This analysis found that field produced by a virus inside ferrofluid can be slightly stronger in magnitude than the corresponding field of a magnetic particle in water. If the sensor were sensitive to magnetic flux density, B, as opposed to magnetic field strength, H, then further increases in the sensor signal can be expected using the ferrofluid immersion approach.