Determination　of　ochratoxin　A　(OTA)　is　highly　important　for　food　safety　control.　In　this　study,　a　signal-on　electrochemiluminescence　(ECL)　biosensor　which　combined　the　characteristics　of　high　efficiency　of　hyperbranched　rolling　circle　amplification　(HRCA)　and　high　selectivity　of　aptamer　was　developed　for　OTA　determination.　The　capture　probe　DNA　(CDNA)　was　firstly　immobilized　on　the　gold　electrode　surface　through　Au-S　interaction,　then　the　OTA　aptamer　was　modified　on　the　electrode　surface　through　hybridization　with　CDNA.　Since　OTA　can　competitively　bind　with　the　aptamer　due　to　their　high　affinity,　which　would　induce　the　releasing　of　aptamer　from　the　electrode　surface.　Subsequently,　the　free　CDNA　on　the　electrode　surface　can　hybridize　with　the　padlock　probe　and　induce　HRCA　reaction　subsequently.　Thus,　the　HRCA　products　which　contained　large　amount　of　double-stranded　DNA　(dsDNA)　fragments　can　be　accumulated　on　the　electrode　surface,　Since　Ru(phen)(3)(2+)　can　intercalate　into　the　groove　of　dsDNA　and　acts　as　ECL　indicator,　high　ECL　intensity　can　be　detected　from　the　electrode　surface.　The　enhanced　ECL　intensity　has　a　linear　relationship　with　OTA　in　the　range　of　0.05-500　pg/mL　with　a　correlation　coefficient　of　0.9957,　and　the　limit　of　detection　(LOD)　was　0.02　pg/mL.　The　developed　biosensor　has　been　applied　to　determine　OTA　concentration　in　the　corn　samples　with　satisfied　results.　(C)　2015　Elsevier　B.V.　All　rights　reserved.