Biologically derived nanomagnets in self-organized patterned media

Self‐Assembling Nanoparticles at Surfaces and Interfaces

“…[192] Mayes et al created highly ordered FePt, and CoPt nanoparticle patterns using apoferritin (demineralized ferritin), which have a cavity in the center. [193] This protein self-assembles into a sphere with a diameter of 12 nm containing a cavity of 7.5-8 nm. Biologically produced ferritin (an iron-storage protein) encapsulates a ferrihydrite (iron oxide), which can be removed chemically to give an empty, spherical ferritin cage (apoferritin) into which particles of CoPt or FePt can be grown, with a narrow size distribution.…”

Bio-inspired Synthesis of Protein-Encapsulated CoPt Nanoparticles

“…[1,3,17] This biomimetic approach has been exploited using the Fe-storage protein, ferritin, to grow CoPt nanoparticles that were subsequently annealed into the ordered L1 0 phase and templated into large 2D arrays. [14,37] Protein engineering via directed evolution and screening of combinatorial peptide libraries using phage display have identified peptide sequences with specific affinity toward inorganic materials that are normally not found under biological conditions. [16±21] These peptides have been shown to be extremely useful in direct materials synthesis using a biomimetic approach.…”

Electrochemically controlled reconstitution of immobilized ferritins for bioelectronic applications

“…Biomineralization of other metals (i.e., Co [9,11], Mn [12][13][14], Ni [15], and Pd [16]), semiconductors (CdS) [17], and metal-oxo-anions composites [18] into the ferritin cavity has also been reported. Wong et al demonstrated the magnetic transition from superparamagnetic to ferromagnetic CoPt cored ferritin [19][20]. Tetrachloroplatinate anion was moved to the ferritin core and fabricated to Pt nanoparticles by chemical reduction.…”