title: Biological colloid engineering: Self-assembly of dipolar ferromagnetic chains in a functionalized biogenic ferrofluid.
abstract: We have studied the dynamic behavior of nanoparticles in ferrofluids consisting of single-domain, biogenic magnetite (Fe(3)O(4)) isolated from Magnetospirillum magnetotacticum (MS-1). Although dipolar chains form in magnetic colloids in zero applied field, when dried upon substrates, the solvent front disorders nanoparticle aggregation. Using avidin-biotin functionalization of the particles and substrate, we generated self-assembled, linear chain motifs that resist solvent front disruption in zero-field. The engineered self-assembly process we describe here provides an approach for the creation of ordered magnetic structures that could impact fields ranging from micro-electro-mechanical systems development to magnetic imaging of biological structures.
authors.forename: Warren C
authors.initials: WC
authors.lastname: Ruder
authors.forename: Chia-Pei D
authors.initials: CP
authors.lastname: Hsu
authors.forename: Brent D
authors.initials: BD
authors.lastname: Edelman
authors.forename: Russell
authors.initials: R
authors.lastname: Schwartz
authors.forename: Philip R
authors.initials: PR
authors.lastname: Leduc