A　cobalt　imidazolate　(im)　framework　material　[Co(im)(2)](n)　was　employed　to　use　as　a　trimethylamine　(TMA)　gas　sensor　and　the　[Co(im)(2)](n)　sensor　can　be　easily　fabricated　by　using　Ag-Pd　interdigitated　electrodes.　Gas　sensing　measurement　indicated　that　the　[Co(im)(2)](n)　sensor　shows　excellent　selectivity,　high　gas　response　and　a　low　detection　limit　level　of　2　ppm　to　TMA　at　75　degrees　C.　The　good　selectivity　and　high　response　to　TMA　of　the　sensor　based　on　[Co(im)(2)](n)　may　be　attributed　to　the　weak　interaction　between　the　TMA　molecules　and　the　[Co(im)(2)](n)　framework.　That　may　provide　an　ideal　candidate　for　detecting　freshness　of　fish　and　seafood.