Design of magnetic akaganeite-cyanobacteria hybrid biofilms

Common Anabaena cyanobacteria are shown to form intra-cellularly akaganeite beta-FeOOH nanorods of well-controlled size and unusual morphology at room temperature. High-resolution transmission electron microscopy showed that these nanorods present a complex arrangement of pores forming a spongelike structure. These hybrid akaganeite-cyanobacteria were used to form one-pot hybrid biofilms. The hybrid biofilm presents higher coercivity (H-c =44.6 kA m(-1) (560 Oe)) when compared to lyophilized akaganeite-cyanobacteria powder (H-c = 0.8 kA m(-1) (10 Oe)) due to the quasi-assembly of the cells on the glass substrate compared to the lyophilized randomly akaganeite-cyanobacteria powder. (C) 2010 Elsevier B.V. All rights reserved.