Selective acetylene detection through surface modification of metal-insulator-semiconductor sensors with alkanethiolate monolayers

Palladium-based metal-insulator-semiconductor sensors were functionalized with self-assembled monolayer coatings derived from alkanethiols with 6, 12, and 18 carbons. The functionalized sensor showed enhanced response to acetylene in a hydrogen background while showing negligible response to a similar gas, ethylene. The presence of sulfur alone on the surface resulted in a small acetylene response, suggesting that palladium-sulfur bond formation plays a role in the response. However, the response of alkanethiol SAM coated sensors was five times greater, indicating that the alkyl chain also affects acetylene detection. (c) 2008 Elsevier B.V. All rights reserved.