Scanned probe investigations of chemically derived nanostructures

We discuss the use of a conducting-tip atomic force microscope (AFM) for the imaging and electrical measurement of chemically derived nanostructures. First, scanning probe microscopy of CdSe and Au nanocrystals bound to a substrate with a self assembled monolayer will be discussed. It is found that imaging in liquids is necessary to avoid removing the nanocrystals. We then address some issues in performing electrical measurements in liquids. In particular, we examine the conducting properties of the AFM tip when imaging a flat surface, highly oriented pyrolytic graphite, in a non-polar liquid, hexadecane. We find that the solvation layers between the tip and the substrate strongly influence the electrical properties.