Molecular adsorption and desorption events probed by frequency domain measurements at atom-scale junctions prepared by self-limiting electrodeposition

COLL 295

Paul W. Bohn, pbohn@nd.edu and Ping Shi, pshi@nd.edu. Department of Chemical and Biomolecular Engineering, University of Notre Dame, 301 Cushing Hall, Notre Dame, IN 46556
Interfacial boundary layer scattering at nanowire surfaces is a mechanism to sense chemisorption, particularly of Lewis bases, and a key challenge is to extract information about chemical dynamics through statistical characterization of current noise in structures supporting ballistic electron transport . These structures are composed of metallic wires which, at the narrowest constriction, are a few Au atoms in the transverse dimension. Current conduction is dominated by ballistic transport, and these structures are exceptionally sensitive to adsorption-induced alterations in electron scattering, the latter being measured through changes in the in-plane conductance. The principal focus of the work to be described is: (1) to understand the role played by dynamic chemical equilibrium in developing chemically derived signals at nanostructured measurement components; and (2) to use this understanding to develop new electrochemical and surface-initiated routes to chemical sensing and stimulus-responsive structures with nanometer-level control over growth and placement of molecular architectures.