Using a light pointer and a flat, unstructured silicon electrode modified with an organic self-assembled monolayer (SAM) with a single ohmic contact, light-activated electrochemistry, or LAE, can spatially resolve electrochemistry. The semiconducting electrode must be biassed into depletion at the redox potential of the species of interest,
the redox couple must be covalently attached to the electrode, and the silicon must be protected from oxidation with a self-assembled monolayer (SAM). These three conditions are necessary for light-activated electrochemistry. Faradic electrochemistry at a monolayer protected monolithic silicon electrode can be "turned on" at any location with micron scale resolution by simply illuminating that area with light, according to the powerful concept of light-activated electrochemistry.