Optical detection of C2 hydrocarbons ethane, ethylene, and acetylene with a photonic crystal made from carbonized porous silicon

Porous photonic crystals consisting of a thin microporous glassy carbon coating on the walls of a mesoporous silicon nanostructure are prepared and evaluated for their ability to sense C2 hydrocarbons. [Display omitted] •Glassy carbon/silicon composite photonic crystals are prepared.•Volatile hydrocarbons ethane, ethylene and acetylene are detected.•LLOD for C2 hydrocarbons is 0.2% (v/v), 10× below flammable limit.•No response to methane or carbon monoxide at concentrations 10 times below the lower flammable limit.