Hydrogen detection using surface plasmon resonance in palladium films

We investigate the performance of Pd films for the development of H
₂
sensors based on the surface plasmon resonance (SPR) effect. Experimental measurements were carried out on glass substrates sputtered with Pd thin films, using a homemade automatic reflectometer based on Kretschmann's prism coupling configuration. The sensitivity for H
₂
detection measured experimentally was approximately 60% lower than that expected from calculations based on the optical constants tabulated in the literature, but exhibited the approximate trend in thickness dependency predicted theoretically. In spite of this difference, these results yield important findings for the design of SPR-based H
₂
sensors with maximum sensitivity.