Biological reduction of nanoengineered iron(III) oxide sculptured thin films.

Sculptured thin films (STFs) are assemblies of nominally identical, parallel nanowires with tailored shapes such as chevrons and spirals. A series of iron(lll) STFs were produced with varied crystallinity (from hematite toferrihydrite) and nanowire shapes (slanted columnar, clockwise helical, and counterclockwise helical). When the dissimilatory metal-reducing bacterium Shewanella putrefaciens CN32 was used to measure their bioreducibility, it was found that bioreduction was controlled primarily by oxide crystallinity.