Template stripped Au substrates were prepared by thermally evaporating 200 nm Au film onto Si (100) wafers. The Si wafers were sonicated in ethanol for 15 min and then immersed in Piranha solution for 30 minutes. Next, these Si wafers were flushed with large amounts of ultrapure water and dried with N 2 prior to use. After deposition, pieces of glass (0.5 cm x 2 cm) were glued onto the surface of Au by a glue (Thorlabs GmbH, Germany) which can be cured by irradiation with UV light (365 nm) for 20 min. The as prepared Au substrates were freshly stripped from the Si wafer before use. The root mean squared roughness (RMS) of these Au substrate is around 0.47 nm, based on STM images.