A　simple,　low-cost,　and　sensitive　liposome-based　colorimetric　aptasensor　has　been　developed　to　detect　ochratoxin　A　(OTA).　Specifically,　a　dumbbell-shaped　probe　was　designed,　including　magnetic　beads　(MBs),　double-stranded　DNA　(dsDNA),　and　enzyme-encapsulated　liposome.　The　dsDNA　formed　by　the　hybridization　between　OTA　aptamer　and　its　complementary　probe.　And　the　dsDNA　was　used　to　contact　the　MBs　and　the　enzyme-encapsulated　liposome.　In　the　presence　of　OTA,　the　aptamer　preferred　to　combine　with　OTA　to　form　G-quadruplex,　resulting　in　the　release　of　the　detection　probe　and　the　enzyme-encapsulated　liposome.　Each　liposome　contained　a　large　amount　of　HRP.　Thus,　when　the　liposome　was　lysed　by　adding　the　mixed　solution　of　3,3′,5,5′-tetramethylbenzidine　(TMB)　and　H2O2,　a　large　number　of　HRP　were　released.　HRP　could　catalyze　the　H2O2-mediated　oxidation　of　TMB　and　hence　resulted　in　the　color　change　from　colorless　to　blue　with　the　OTA　concentration　varying,　and　this　variation　can　be　observed　by　naked　eyes　easily.　The　result　showed　that　the　absorption　intensity　at　652　nm　enhanced　with　the　increase　of　OTA　concentration　ranging　from　0.05　to　2.0　ng　mL−1,　and　the　limit　of　detection　was　calculated　to　be　0.023　ng　mL−1　(S/N　=　3).　The　developed　colorimetric　aptasensor　has　been　applied　to　detect　OTA　concentration　in　corn　samples　with　satisfied　results.　©　2017　Elsevier　B.V.