[K(DB18-C-6)]2Cu(SCN)4 was synthesized, and characterized by elemental analysis and IR. An optical
waveguide gas sensor based on [K(DB18-C-6)]2Cu(SCN)4 was fabricated by the method of spin-coating. The
experimental results showed that, the sensor has a better response to ethanediamine gas. The sensor can detect ethanediamine gas with the concentration of lower than 1 x 10-8 (volume ratio).