Novel Method for Uni-size Magnetic Nanoparticle Preparation and Their Efficient Modification for Bio/Chemical Separation

In recent years, the integration of nanotechnology with biology, chemistry and medicine has utilized functionalized nanoparticles in molecular diagnostics, therapeutics, molecular biology, bioengineering, separation science and even bio-separation. Also, all kinds of functionalized nanoparticles have been developed; in particular substantial progress has been made in magnetic nanospheres and ferrofluids developement technologies. Due to their size-dependent properties and dimensional similarities to bio-macro-molecules, these magnetic nanoparticles can be used as contrast agents for in vivo magnetic resonance imaging (MRI), as long-circulating carriers for drug release/delivery, and potentially as oligonucleotide and chemical spices separation devices in medicine and biotechnology. Isolation of the materials by magnetic method is faster than even liquid chromatography and electrophoresis techniques. Also, target molecules such as peptides, proteins, and oligonucleotides can be separated and recovered from untreated crude samples without any filtration and pretreatment steps by magnetic conjugates, i.e., by attaching biospecific ligands. In fact, this novel nanocapture agent is a kind of magnetic nanoparticle which incorporates desired probes. Probe could immobilize on the nanoparticles by using of weak electrostatic interaction. Such linking is not stable, which will affect the lifetime of the nanocapture agent. Also there is another immobilization method which uses covalent bonding to immobilize the ligand to particles. This kind of bonding makesparticles and probes so stable against the separation conditions. As known, the lifetime and the efficiency of separation and recovery are two important factors to the nanocapture agent.