A　portable　sensor　using　the　height　of　the　liquid　column　in　capillary　as　readout　was　designed　for　detection　of　hydrogen　sulfide　(H2S).　Cuprous　ion　(Cu+　)　could　induce　the　combination　of　azide-modified　magnetic　beads　(MBs-N3)　and　alkyne-modified　platinum　nanoparticles　(　Pt　NPs-Alk)　through　click　chemistry　to　form　platinum　nanoparticles　connected　to　magnetic　beads　(MBs-Pt　NPs).　MBs-Pt　NPs　could　be　separated　from　the　reaction　mixture　by　magnetic　force　and　transferred　to　a　glass　bottle　filled　with　hydrogen　peroxide　(H2O2)　solution　with　a　capillary　on　bottle　cap.　In　the　above-mentioned　closed　reaction　device,　H2O2　was　catalytically　decomposed　by　Pt　NPs　and　generated　a　large　amount　of　oxygen,　which　caused　the　liquid　column　in　the　capillary　to　rise.　In　the　presence　of　H2S,　the　azide　groups　on　the　surface　of　MBs-N3　could　be　reduced　to　amino　groups　by　H2S,　thereby　reducing　the　click　chemistry　reaction　sites　between　it　and　Pt　NPs-Alk,　ultimately　leading　to　a　reduction　in　the　catalytic　efficiency　of　H2O2　decomposition　and　a　reduction　in　the　rising　height　of　the　capillary　liquid　column.　The　change　of　height　of　the　liquid　column　in　the　capillary　had　a　linear　relationship　with　H2S　concentration　in　the　range　of　2.　0　to　60　mu　mol/　L,　and　the　limit　of　detection　was　1.　9　mu　mol/　L.　The　method　was　used　for　the　rapid　and　simple　determination　of　H2S　in　red　wine　with　satisfactory　results.