There is an amazing story in about two research teams who have managed to create single molecule transistors.

The ability to use individual molecules for electronics is a coveted breakthrough for science at the nanometer scale and for electronics industries because of the potential to shrink the size of components well beyond what is possible using conventional lithography techniques.

Transistors, traditionally made from silicon, regulate the transmission of electrons across barriers. The barrier height, and hence the electron flow, can be controlled by applying a small voltage to an electrode that acts as a gate.