Nanostructured Silver Films for Surface Plasmon Resonance-Based Gas Sensors

We report the room temperature detection of carbon monoxide (CO) and hydrogen (H₂) by nanostructured silver films via surface plasmon resonance (SPR) phenomena. Thin films of Ag and yittrium stabilized zirconea (YSZ): Ag were prepared by pulsed laser deposition (PLD) method. Films were characterized by XRD and atomic force microscopy. CO and H₂ are selected as the target gases for the YSZ: Ag films and the sensor characteristics are compared. Sensitivity was estimated by percent change in wavelength for SPR band peak. The nanostructured films were tested for different concentration of CO (100 to 1000 ppm) and hydrogen (1 to 10%). The sensors were also tested for the cross selectivity of the gases. The sensors have a detection limit of 100 ppm for CO and also show a noticeable signal for hydrogen in the concentration range as low as 1%.