ANYL 23 |
| Small scale synthetic motors capable of generating their own motive forces by exploiting the chemical free energy of their environment represent an important step in developing practical nanomachines. Catalytic particles are capable of generating concentration and other gradients that can be used to self-propel small objects. However, the autonomous movement of catalytic nanoparticles by self-generated forces is a relatively unexplored area in colloid and interfacial chemistry. We have shown that Pt-Au nanorods are catalytically self-propelled in aqueous hydrogen peroxide solutions. In this case, the mechanism of energy transduction involves an interfacial tension gradient generated by a chemical concentration gradient. Electrochemical studies of hydrogen peroxide electrochemistry at metal ultramicroelectrodes, coupled to kinetic measurements of oxygen evolution, show that other modes of propulsion such as self-electrophoresis should be possible in some geometries. We are currently studying additional reactions, in particular enzymatically catalyzed hydrogen peroxide decomposition and catalytic oxidation-reduction reactions, as means of converting chemical to mechanical energy in nano- and microscale motors. |
|
New Frontiers in Ultrasensitive Analysis: Nanobiotech, Single Molecule Detection, and Single Cell Analysis
8:30 AM-11:45 AM, Sunday, 28 August 2005 Washington DC Convention Center -- 152B, Oral
Division of Analytical Chemistry |