Nano-film has many special characters for its highly surface activity

one of which is the gas-sensitivity.The in-plane resistivity of nanogold film can be changed after it adsorbed sulphydryl compounds.In the experiment nanogold film whose thickness is about 15 nm on different substrates is got by ion sputtering

and the changing rule of current to the gold film is researched by virtue of bridge-testing circuit when the film adsorbed n-propanethiol.Experimental data shows that nanogold film can detect very low volume fraction of gas

which is about 20×10-6only.