Smart Magnetically Engineering Colloids and Biothin Films for Diagnostics Applications

Novel iron oxide based magnetic colloids were employed to fabricate bio-thin films and also explored for their in vitro magnetic resonance imaging (MRI) characteristics. Magnetic colloids contained functional groups on their surfaces and thus facilitated the formation of thin films via facile technique of layer-by-layer self-assembled multilayers formation. Adsorption of colloids on the substrates surface was controlled through various parameters including varying numbers of bilayers. SEM and AFM analyses clearly demonstrated that colloids were adsorbed as such with spherical morphologies. In addition, substrate coverage was found to increase with number of layers and time. The used magnetic colloids were also employed to acquire MRI images to explore their potential for future contrast agents for cancer diagnostics. Both T-1 (spin-lattice or longitudinal relaxation time) and T-2 (the spin-spin or transverse relaxation time) relaxation times were successfully measured. On the basis of contrast information, the magnetic colloids observed to perform better as T2 type of contrast agent. The research work reported here open new avenues to employ the novel biothin film for various biomedical applications such as virus captures, analysis of biomacromolecules, DNA, RNA, etc., and magnetic colloids for various diagnostics and imaging applications including the MRI.