Cryptophane A-Based Methane Sensing in the Aqueous and Gas Phase

Methane is a crucial environmental parameter. However, the range for dissolved methane sensors must be expanded, as it lacks small, submersible sensors with sub-ppm resolution. In 2008, Boulart reported the development of a promising prototype. The sensor based on surface plasmon resonance (SPR) measurements of a polymer membrane doped with Cryptophane A (CryptA). Unfortunately, the work on this prototype was discontinued in 2013. In this study, an aqueous and gas-phase methane sensor was constructed with the objective of reproducing and enhancing the results reported by Boulart. However, as with other approaches based on CryptA, a sub-ppm resolution was not achieved. The crucial difference of Boulart's approach lies within an unexplainable high methane sensitivity of their polymer membrane.