Magnetic Gold Nanoshells: Step-wise Changing of Magnetism through Step-wise Biofunctionalization.

We report step-wise changing of magnetic behavior of iron oxide core gold shell nanoparticles from super paramagnetic to permanent magnetism at room temperature, on step-wise bio-functionalization with leutenizing hormone and releasing hormone (LHRH) through cysteamine linker. The observed permanent magnetism at room temperature in LHRH-capped gold nanoshells provides opportunities to extend fundamental investigations of permanent magnetism to other novel nanostructures and biofunctionalized nano gold architectures, simultaneously opening the way to newer applications, especially to those in biomedicine.