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.