Magnetic nanoparticles can be used to load bio–molecules for various biophysical applications. The direct attachment of bio–molecules such as protein and DNA to magnetic nanoparticles may lead to alter their structure. A method to immobilize and store biomolecules for example DNA on to a magnetic nanoparticles surface without much structural alteration is carried out in the present work. DNA is a target for many therapeutic small molecules as therapeutic drugs bind to DNA – interfering with protein factors involved in DNA mechanism, or cleave DNA cross-link – interfering with the cell division. This may find applications in drug interactions study with the stored DNA without much alteration in their structure.