The transparent conductive thin films used as electrodes for plasma device applications can be damaged by the background plasma with a resulting spectral alteration of the optical emission of the device, In this work, we studied the surface damage experienced by a plasma-based artificial nose by a combination of surface sensitive techniques. Atomic force microscopy and glancing incidence low, kV scanning electron microscopy show no change of microstructure. Energy dispersive X-ray analysis over a range of low electron energies reveals that the oxide has been reduced. This is confirmed by depth sensitive nanoindentation measurements, which indicate that the hardness and Young modulus are lower for the damaged surface.