Fabrication of Clean Nanogaps Using a Combined Electrochemical–Chemical Method

Fabrication of clean nanogaps is achieved using combined electrochemical/chemical etching of microfabricated gold wires in an iodine‐based solution. In contrast to simple chemical etching, all visible spurious metal grains are removed while the gap is forming (see image). Obtained gaps have a controlled size between 1 and 10nm, which is suitable to connect small molecules or nanoparticles.