Nitrogen　and　sulfur　codoped　carbon-based　dots　(N,S-CDs)　with　strong　blue　light　emission　are　encapsulated　into　red　light-emitting　europium　metal-organic　frameworks　(Eu-MOFs)　to　form　two　color　light-emitting　nanohybrids　(Eu-MOFs/N,S-CDs).　In　organic　solvents,　the　encapsulated　N,S-CDs　are　aggregated　and　confined　in　the　cavities　of　the　Eu-MOFs,　exhibiting　only　a　very　weak　photoluminescence　(PL)　signal.　Therefore,　the　nanohybrids　show　red　light　emission　of　the　Eu-MOFs.　Contrarily,　when　the　Eu-MOFs/N,S-CDs　are　dispersed　in　water,　the　encapsulated　N,S-CDs　are　released　into　solution　while　the　red　light　emission　of　the　Eu-MOFs　is　quenched　due　to　the　effect　of　O-H　oscillators.　The　nanohybrids　are　used　as　the　probe　for　the　water　content　in　organic　solvents.　Take　ethanol　as　an　example;　as　the　water　content　is　increased　from　0.2　to　30%,　the　nanoprobe　provides　distinguishable　PL　color　change.　The　ratio　of　light　intensity　at　420　nm　to　that　at　623　nm　(I420/I623)　increases　linearly　with　increasing　water　content　in　the　range　from　0.05　to　4%　with　a　low　detection　limit　of　0.03%.　©　2016　American　Chemical　Society.