Hello all, I'm currently working on a gas sensor using Au electrodes. The electrodes has a 1 um gap with ~0.5 um thick of SiO2 layer underneath. Without adding any semiconductor layers on top of the electrodes, I've got the R reading changed relevant to the presence or absence of testing gases, methanol for example. I don't know how this could happen.I wonder if anyone has the same experience that can share your idea to me. Any responses would be greatly appreciated. Terry