Planar resonant tunneling sensor devices and methods for using the same are provided. The subject devices include first and second electrodes present on a surface of a planar substrate and separated from each other by a nanodimensioned gap. The devices also include a first member for holding a sample, and a second member for moving the first member and planar resonant tunneling electrode relative to each other. Also provided are methods of fabricating such a device and methods of using such a device for improved detection and characterization of a sample.