A　simple　strategy　for　encapsulating　choline　oxidase　(ChOD)　into　the　titanate　nanotubes　(TNTs)　and　Nafion　composite　film　for　choline　sensing　was　proposed.　Hydrogen　peroxide,　as　the　product　of　the　redox　enzymatic　reaction,　could　enhance　the　ECL　of　luminol.　Therefore,　the　substrates　of　corresponding　redox　enzymes　could　be　detected　indirectly　through　the　determination　of　hydrogen　peroxide　in　the　luminol　ECL　system.　Through　this　approach,　it　was　found　that　ChOD　could　be　fixed　firmly　into　the　TNTs　contained　composite　film.　TNTs　would　not　only　offer　excellent　photocatalytic　activity　toward　luminol-H2O2　ECL　system,　but　also　provide　a　shelter　for　the　biomolecules,　such　as　redox　enzyme　to　retain　its　bioactivity.　©　2009　Elsevier　B.V.　All　rights　reserved.