Biomolecular rods and tubes in nanotechnology

Biomolecules are vitally important elements in nanoscale science and also in future nanotechnology. Their shape and their chemical and physical functionality can give them a big advantage over inorganic and organic substances. While this becomes most obvious in proteins and peptides, with their complicated, but easily controlled chemistry, other biomolecular substances such as DNA, lipids and carbohydrates can also be important. In this review, the emphasis is on one-dimensional molecules and on molecules that self-assemble into linear structures, and on their potential applications. An important aspect is that biomolecules can act as templates, i.e. their shape and chemical properties can be employed to arrange inorganic substances -- such as metals or metal compounds -- on the nanometre scale. In particular, rod- and tube-like nanostructures can show physical properties that are different from those of the bulk material, and thus these structures are likely to be a basis for new technology.