Recently, research activities aim to develop information storage systems consisting of functional chemical units as alternatives to magnetic-or semiconductor-based memory technologies. Different stimuli that include light signals, [1] electrical, [2] or chemical [3] inputs, were coupled as signals for the activation of "write-read-erase" systems. The integration of chemical functions with surfaces, specifically electrodes, enables the combination and coupling of different signals to design erasable "write" and "read" systems. The photochemical isomerization of azobenzene monolayers demonstrated the ability to register information by the trans-cis photoisomerization of the azobenzene units and the information readout, and erase by the electrochemical activation of the photoisomerized units. [4] Reversible photoisomerization of monolayer assemblies associated with electrodes and the redox-readout of the monolayer states provide a method to store and read the information, as well as to erase it upon demand. [5] Similarly, the electrochemical activation of a composite redox-active monolayer was used to encode and readout information. The programmed photochemical or electrochemical [8] mechanical translocation of molecular components on molecular wires was recently employed for information storage. One major challenge in information storage relates to the storage density. Most of the commercial memories are two-dimensional arrays with a density of approximately 0.2 mm 2 per bit. Different approaches to miniaturize the storage devices were suggested, including the use of scanning probe microscopes such as the electrochemical encoding of information in WO 3 films using scanning electrochemical microscopy, or the simple electron charging of individual metallic nanoparticles by scanning tunneling microscopy. [11] Here we wish to report on the development of "writeread-erase" electrochemical information storage systems based on stripping voltammetry of metals. While most of the available information storage systems require the two-or three-dimensional encoding of information in spatially resolvable structures, the present method enables the storage and readout of the information in a simple confined structure that does not involve spatial resolution and is based on the structure composition.
Stripping voltammetry is a powerful tool for the detection of trace metals down to the sub-ppb range. For decades mer-[a] Dr.