Meso-porous membrane of noble metal for surface plasmon resonance gas sensors
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Since surface plasmon resonance (SPR) provides quick response and high sensitivity to environmental substances, it is recognized as a powerful technique for toxic gas detection system [1, 2, 3]. Although already reported SPR gas sensors have achieved a high sensitivity at the ppm level, the adsorption of vapor molecules relies only on the affinity of the planar surface of the sensitive membrane. In terms of adsorption efficiency, a planar adsorber element is less advantageous because the specific surface area is small. It is expected that the sensitivity of the SPR gas sensor could be improved by introducing a porous structure to the sensor surface. However, in order to excite SPR at optical frequencies, materials are limited to Ag or Au on account of the dielectric permittivity to achieve wavenumber matching. These noble metals are stable both chemically and physically, and fabrication of a nano-sized porous structure on these metals has been difficult.
In this letter, a meso-porous...
KeywordsSurface Plasmon Resonance Surface Profile Adsorption Efficiency Deposition Thickness Vapor Molecule
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