Studying single ions and molecules with atomic-scale wires and gaps

Arizona State University, Scottsdale AZ

Investigators

Abstract

Professor Nongjian Tao of Arizona State University is supported by the Analytical and Surface Chemistry Program to fabricate atomic-scale metal wires with quantized conductance. Metal is deposited or etched electrochemically. Electrochemical processes such as charge transport and adsorbate effects are studied. This project focuses on relatively simple ions and redox molecules in electrolyes and their interaction with the nanowires. Single ions and molecules are detected via tunneling currents as they trap in or escape from a molecular-scale gap. The project relates to the goals of miniaturizing electronics to molecular-size scale. Students enjoy interdisciplinary training in electrochemistry and nanofabrication skills and benefit from close collaboration with Motorola. The fabrication method from this lab has found applications in a number of labs around the world, making reliable single molecule measurements more available for development. Studies on solvation and ions are required to understand the characteristics of the nanowires in complex environments such as analytic samples and single biological cells.