Pierre-Yves Blanchard

Scanning Electrochemical Microscopy Study of Permeability of a Thiolated Aryl Multilayer and Imaging of Single Nanocubes Anchored to It.

Electroreduction of diazonium salts is a widely used technique for grafting organic films on various surfaces. In this paper, scanning electrochemical microscopy (SECM) was used for high-resolution characterization of a thiolated aryl multilayer film obtained by electrografting of thiophenol diazonium on highly ordered pyrolytic graphite (HOPG). The blocking properties of the film were evaluated, and the origins of incomplete surface passivation were elucidated by comparing current-distance curves and surface reactivity maps obtained with nanometer- and micrometer-sized tips. In this way, one can distinguish between different pathways of charge transport in the film, e.g., pinhole defects versus rate-limiting charge transfer through the film. Pd nanocubes were anchored to the film by thiol groups and imaged by SECM. The applicability of SECM to in situ visualization of the geometry of non-spherical nanoparticles has been demonstrated.

Electrochemical transduction on self-assembled monolayers: are covalent links essential?

Electrochemical transduction without covalent links between redox and complexant units in a complexing self-assembled monolayer has been established. The results demonstrate that transduction depends on the crown ether/ferrocene ratio and appears to be tunable.

Evidence of electrochemical transduction of cation recognition by TEMPO derivatives

This work reports the first example of electrochemical cation binding transductionvianitroxyl groups. It shows the possibility to transduce a complexation without a π-conjugated bridge between the redox and the host moieties. As expected, we confirm that the host/redox probe distance is a key point for transduction.