Graphene　is　a　single　layer　of　carbon　atoms　with　a　large　surface-to-volume　ratio,　providing　a　large　capacity　gas　molecule　adsorption　and　a　strong　surface　sensitivity.　Chemical　vapor　deposition-grown　graphene-based　NO2　gas　sensors　typically　have　detection　limits　from　100　parts　per　billion　(ppb)　to　a　few　parts　per　million　(ppm),　with　response　times　over　1000　s.　Numerous　methods　have　been　proposed　to　enhance　the　NO2　sensing　ability　of　graphenes.　Among　them,　surface　decoration　with　metal　particles　and　metal-oxide　particles　has　demonstrated　the　potential　to　enhance　the　gas-sensing　properties.　Here,　we　show　that　the　NO2　sensing　of　graphene　can　be　also　enhanced　via　decoration　with　monodisperse　polymer　beads.　In　dark　conditions,　the　detection　limit　is　improved　from　1000　to　45　ppb　after　the　application　of　polystyrene　(PS)　beads.　With　laser　illumination,　a　detection　limit　of　0.5　ppb　is　determined.　The　enhanced　gas　sensing　is　due　to　surface　plasmon　polaritons　excited　by　interference　and　charge　transfer　between　the　PS　beads.　This　method　opens　an　interesting　route　for　the　application　of　graphene　in　gas　sensing.