Cost-effective design of high-magnetic moment nanostructures for biotechnological applications.

Disk-shaped magnetic nanostructures present distinctive features for novel biomedical applications. Fine tuning of geometry and dimensions is demanded to evaluate efficiency and capability of such applications. This work addresses cost-effective, versatile and maskless design of biocompatible high-magnetic moment elements at the sub-micrometer scale. Advantages and disadvantages of two high throughput fabrication routes using interference lithography were evaluated. Detrimental steps as the release process of nanodisks into aqueous solution were optimized to fully preserve the magnetic properties of the material. Then, cell viability of the nanostructures was assessed in primary melanoma cultures. No toxicity effects were observed, validating the potential of these nanostructures in biotechnological applications. The present methodology will allow the fabrication of magnetic nanoelements at the sub-micrometer scale with unique spin configurations, such as vortex state, synthetic antiferromagnets, or exchange-coupled heterostructures, and their use in biomedical techniques that require a remote actuation or a magneto-electric response.