A　novel　competitive-type　immunosensing　strategy　based　on　target-induced　displacement　reaction　with　antibody-functionalized　mesoporous　carbon　(MSC)　nanoparticles　was　designed　for　sensitive　and　rapid　electrochemical　detection　of　aflatoxin　B1　(AFB1,　used　as　a　model)　on　the　Nafion-functionalized　sensing　interface.　Electroactive　thionine　molecules　were　initially　decorated　to　the　mesoporous　carbon,　and　polyclonal　anti-AFB1　antibody　was　then　covalently　conjugated　to　the　nanostructures.　The　immunosensor　was　simply　prepared　via　the　electrostatic　interaction　between　negatively　charged　Nafion　film　and　positively　charged　anti-AFB1　antibody　accompanying　the　nanostructures.　The　electrochemical　signal　originated　from　the　carried　thionine　to　mesoporous　carbon.　Upon　target　AFB1　introduction,　the　analyte　reacted　with　the　labeled　anti-AFB1　antibody　on　the　MSC　based　on　specific　antigen-antibody　reaction　and　induced　the　dissociation　of　thionine-MSN　nanostructures　from　the　sensing　interface,　thus　decreasing　the　cathodic　current　of　the　carried　thionine　molecules.　Under　optimal　conditions,　the　immunosensor　exhibited　good　electrochemical　responses　for　determination　of　target　AFB1　at　a　concentration　as　low　as　3.0　pg　mL-1　(3.0ppt).　Importantly,　the　non-conventional　sensing　system　provides　a　promising　immunosensing　strategy　for　rapid　screening　of　small　molecules　because　of　its　simplicity,　low　cost　and　sensitivity　without　the　needs　of　sample　separation　and　washing　step.　©　2015　Elsevier　B.V.