We report on a simple method to fabricate, under ambient conditions and within seconds, Schottky nanodiodes using electrospun polyaniline nanofibers and an inorganic n-doped semiconductor. In addition to being a rectifier, the advantage of our design is the complete exposure of the rectifying nanojunction to the surrounding environment, making them attractive candidates in the potential fabrication of low power, supersensitive, and rapid response sensors as well. The diode parameters were calculated assuming the standard thermionic emission model of a Schottky junction, and the use of this junction as a gas sensor was examined.