Rethinking Cryptophane-A for Methane Gas Sensing: Cross-Sensitivity to N₂ and CO₂ at Ambient Conditions.

ABSTRACT: Since the affinity of Cryptophane-A for methane was first reported in 1993, cryptophane-doped polymer films have been extensively studied as enrichment cladding layers in plasmonic, fiber-optic, and integrated waveguide-based optical sensors. While the use of cryptophane-doped layers has improved methane sensitivity compared to undoped claddings, controversy has grown over the years regarding their claimed selectivity and practical applicability. In this work, we employ Raman spectroscopy to provide direct and unambiguous evidence that Cryptophane-A exhibits measurable affinity for three major atmospheric gases (carbon dioxide, methane, and nitrogen) at room temperature, debunking old beliefs of cryptophane-methane selectivity and reformulating the role of nitrogen. Notably, carbon dioxide

SUBMITTER: Alberti S 

PROVIDER: S-EPMC12529469 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature