Researchers at the Univ. of California, Santa Barbara (UCSB) have reported the successful binding of a biological material - peptides (which are short chains of amino acids) - to inorganic semiconducting materials. This is seen as the first step in creating a whole new materials assembly technique that will operate on the nanoscale.

Most semiconducting devices are made from the top down, meaning that a substance is subtracted from a bulk material to make a chip by etching. The new technique aims at building from the bottom up i.e., atom by atom or molecule by molecule.

Evelyn Hu, professor of electrical and computer engineering and director of the Center for Quantized Electronic Structures at UCSB explains: "The techniques we have developed for working with semiconducting materials on the microscale are not adequate for working on the nanoscale. We face challenges in how to integrate nanoscale components to build complex structures, but nature does just that all the time. So the idea behind this research is to mimic nature and build electronic devices the way nature would."

The new approach involves isolating viruses containing peptides that will bind to materials such as gallium arsenide, indium phosphide, or silicon materials not usually thought to have affinities to peptides. Peptides have been identified that not only bind to the inorganic materials but can also distinguish between different crystal orientations of gallium phosphide. The researchers are also designing "bivalent synthetic peptides with two-component recognition," which "have the potential to direct nanoparticles to specific locations on a semiconductor structure. These organic-inorganic pairs should provide powerful building blocks for the fabrication of a new generation of complex, sophisticated electronic structures," says Hu.