Investigators from the research groups of Dr. Klaus Kern at the Max Planck Institute for Solid State Research in Stuttgart (MPI) and of Mario Ruben at the Karlsruhe Institute of Technology (KIT) created a surface slime, composed of molecules with predetermined functions, and observed a fascinating self organization of these molecules into nanostructures. Scientists believe that their findings are a direct example, and a possible way, on how to create simple life forms. Furthermore, they believe that their nanostructures, reported in the Proceedings of the National Academy of Sciences, “also hold great promise as an efficient avenue to new catalysts, nanotechnologies, and surface applications.”
… this observation of molecular organization at surfaces may lead to further insight of how simple, inanimate molecules can build up biological entities of increasing structural and functional complexity, such as membranes, cells, leaves, trees, etc. “The ability of molecules to selectively sort themselves in highly organized structures is a fundamental requirement for all molecular based systems, including biological organisms,” explains Prof. Dr. Klaus Kern, director of the Nanoscale Science Department at the MPI.
Dr. Mario Ruben’s research team at KIT is responsible for designing molecules with built-in instructions, which when read out activate the self-selection process. He comments: “Spontaneous ordering from random mixtures only occurs when built-in instructions are carefully designed and sufficiently strong to initiate successful self-selection.”
Scientists at the MPI directly observe the basic step of self-selection by imaging grid-like assemblies of molecules, which have sorted themselves by size. The features of the grid pattern are about one nanometer in size (0.000 000 001 meters), so small that they can only be imaged using state-of-the-art, ultra sensitive microscopy techniques. “Creating such miniscule architectures with features 50 000 times smaller than a hair is not a simple task,” according to Dr. Steven Tait of the MPI. “Carving these nanometer structures with current technology would be inefficient and extremely expensive. Our strategy is to utilize instructed building blocks which can arrange themselves into desired structures.”
The molecules are placed on ultra-clean metal surfaces and heated gently to enable motion, sorting, and organization. “The molecule movement on the copper surface is restricted to two-dimensions, but is still efficient enough to allow mixing of the molecules. By placing the molecules on a surface, we have the enormous advantage of being able to use specialized microscopes to ‘see’ the nanometer scale structures of the molecular assemblies,” explains Alexander Langner, a graduate student at the MPI and first author of the study.