I propose to explore the frontiers of electrochemistry at the nanometer scale by developing new experimental approaches based on lithographically fabricated fluidic nanodevices. This will allow groundbreaking experiments on a broad range of fundamental topics including double layer structure, screening in ionic liquids, nanoscale hydrodynamics and the dielectric response of single macromolecules. It will also lay the foundations for new analytical techniques based on electrochemical single molecule recognition and targeted at integration with state-of-the-art electronics on a single chip. The latter combination could potentially bring about a revolution in (bio)sensing technology on a scale comparable to those which have already taken place in computing and communications. My first focus will be on nanofabricating sub-femtolitre channels and chambers in which single or small numbers of redox-active molecules can be detected and manipulated using electrochemistry at pairs of embedded electrodes. Simultaneously, I will explore the capabilities electrochemical impedance spectroscopy using nanoelectrodes at frequencies up to 200 MHz. Such a combination of ultra-short length scales and high frequencies has heretofore remained inaccessible and will be made possible here by using electrodes that form an intrinsic part of an integrated detection circuit. This research has a truly exploratory character, as few investigators so far have attempted to combine nanofluidics, modern microelectronics and electrochemistry. Doing so will test our microscopic understanding of electrochemical processes, enable new classes of experiments, and push the limits of electrochemistry as an analytical method. There is thus a high likelihood that further new concepts and applications will emerge over the course of this multidisciplinary program.