The invention relates to novel sensors of the catalytic gas-sensing thin-film metal surface type wherein the surface has an inorganic protective membrane coating formed by a pulsed dc sputtering technique. Preferably, the thin-film metal surface is a Pd, Pt, Ni, Au, Ag or an alloy thereof. The inorganic membrane is of the formula MaObNcCd where M is a metal or semiconductor, O is oxygen, N is nitrogen, and C is carbon and a, b, c, and d can each independently range from zero to seven with the proviso that at least two of a, b, c, and d are non-zero. The sensor design is particularly useful for various hydrogen sensing applications. The invention also includes their method of manufacture.
 The research carried out in connection with this invention was supported by The United States Department of Energy Grant No. DE-FC07-OOCH11031. Accordingly, the United States Government may have certain rights in this invention.