Fabrication of gold microelectrodes on a glass substrate by femtosecond-laser-assisted electroless plating

We present a simple method for fabrication of gold microelectrode by use of femtosecond laser modification combined with successive electroless gold plating. The fabrication procedures mainly include (1) femtosecond laser direct writing for generation of silver seeds, (2) electroless plating for selective growth of gold in areas modified by femtosecond laser irradiation, and (3) postannealing at 300°C for 1 hr for improving adhesion. We find that for successfully achieving selective deposition of gold, the composition of plating solution needs to be carefully chosen and optimized. We demonstrate good electrical conductivity and excellently adhesion of the microelectrode.