Actin-based metallic nanowires as bio-nanotransporters.

The synthesis of conductive nanowires or patterned conductive nanoelements is a challenging goal for the future fabrication of nanoscale circuitry. Similarly, the realization of nanoscale mechanics might introduce a new facet to the area of nanobiotechnology. Here we report on the design of conductive and patterned actin-based gold nanowires, and on the ATP-driven motility of the nano-objects. The polymerization of G-actin labelled with Au nanoparticles, followed by the catalytic enlargement of the nanoparticles, yields gold wires (1-4 microm long and 80-200 nm high) exhibiting high electrical conductivity. The polymerization of the Au nanoparticle/G-actin monomer followed by the polymerization of free G-actin, or alternatively the polymerization of the Au-nanoparticle-labelled G-actin on polymerized F-actin followed by the catalytic enlargement of the particles, yields patterned actin-Au wire-actin or Au wire-actin-Au wire nanostructures, respectively. We demonstrate the ATP-fuelled motility of the actin-Au wire-actin filaments on a myosin interface. These actin-based metallic wires and their nanotransporting funcionality introduce new concepts for developing biological/inorganic hybrid devices.