Use of magnetic nanoparticles as nanosensors to probe for molecular interactions.

Biocompatible magnetic nanosensors have been designed to detect molecular interactions in biological media. Upon target binding, these nanosensors cause changes in the spin-spin relaxation times of neighboring water molecules, which can be detected by magnetic resonance (NMR/MRI) techniques. These magnetic nanosensors have been designed to detect specific mRNA, proteins, enzymatic activity, and pathogens (e.g., virus) with sensitivity in the low femtomole range (0.5-30 fmol).