DNA "Glue" Creates Advanced Materials

A University of Pennsylvania research team has developed a process in which tiny particles spontaneously assemble themselves into 3-D crystalline structures. The "glue" holding the particles together is made of specially designed DNA molecules.

Materials composed of these particles represent a new class of advanced materials. They promise truly unique and useful optical and electronic properties. Potential applications range from improved optoelectronic switches and lasers, to super-resolution optical microscopes and molecular sensors.

If the structures assembled from these particles can interact with light, as semiconductors in conventional computers interact with electrons, they may make possible light-based computing. This approach performs tasks over a million times faster than today's computers. This work also demonstrates the use of experimental methods using customized molecules to build increasingly complex microstructures and nanostructures. This could be a step toward micro-manufacturing, which offers the potential for advanced materials and devices with a broad range of new capabilities.

In the past, using DNA-molecular-based glues to direct the self-assembly of particles into 3-D structures was a challenge. In this research, led by Talid Sinno, computer simulations were used to predict the formation of nuclei and the growth process of these crystal structures. The researchers then verified the predictions by growing highly ordered crystals.

To initiate self-assembly, particles must attract each other. To achieve this attraction the researchers turned to DNA. Single-strand DNA molecules spontaneously form the familiar DNA double helix when they come into contact with compatible molecular sequences. By incorporating strands of DNA into each particle, the researchers induced particle-to-particle interactions. Altering the DNA sequences or the concentration of particles allowed for variation in the particle assembly.