The design, realization, and test performances of an electronic junction based on single-electron phenomena that works in the air at room temperature are hereby reported. The element consists of an electrochemically etched sharp tungsten stylus over whose tip a nanometer-size crystal was synthesized. Langmuir-Blodgett films of cadmium arachidate were transferred onto the stylus and exposed to a H2S atmosphere to yield CdS nanocrystals (30-50 A in diameter) imbedded into an organic matrix. The stylus, biased with respect to a flat electrode, was brought to the tunnel distance from the film and a constant gap value was maintained by a piezo-electric actuator driven by a feedback circuit fed by the tunneling current. With this set-up, it is possible to measure the behavior of the current flowing through the quantum dot when a bias voltage is applied. Voltage-current characteristics measured in the system displayed singleelectron trends such as a Coulomb blockade and Coulomb staircase and revealed capacitance values as small as 10-19 F.For several years, single-electron phenomena have attracted the interest of researchers from basic and applied viewpoints (1-5). These kinds of phenomena can take place when a small conductive particle is placed between two electrodes and is spaced asymmetrically from them by two tunneling gaps. In this case, a quantized charging of the particle resulting in the quantized increase of the current that flows through the system when a bias voltage is applied is observed. The conditions for achieving such a situation imply that the capacitance C of the structure is small enough to make the charging energy of the junction (e2/2C) exceed the thermal energy kT. Namely, roomtemperature monoelectron junctions typically require particles not larger than several nanometers in diameter (quantum dots) (6-9).The possibility of controlling the signal at the level of a single electron will allow the realization of a new class of devices (3)(4)(5)10). These new electronic junction can be foreseen to display very low energy consumption, an ultra-high scale of integration, and fast commutation time.The increasing interest in monoelectron phenomena has stimulated researchers to develop techniques for forming suitable junctions. The main efforts have focused upon the minimization of the element sizes by exploiting lithography processes. Striking results have been recently achieved in this field (11-13). As an alternative to this approach, techniques for nanoparticle formation, localization, and contacting with scanning tunneling microscope (STM) tip have been developed. Consequently, low (14-18) and room (6, 7) temperature monoelectron phenomena have been reported on nanoclusters of various natures and have been synthesized by different methods involving physical and chemical approaches. Among the different methods for producing these granules, one of the most promising seems to be that based on the synthesis of nanometer-size semiconducting granules from LangmuirBlodgett (LB) film precursors (7)....