This　study　demonstrates　a　facile　and　feasible　strategy　toward　the　development　of　advanced　electrochemical　immunosensors　based　on　chemically　functionalized　magnetic　mesoporous　organic　inorganic　hybrid　nanomaterials,　and　the　preparation,　characterization,　and　measurement　of　relevant　properties　of　the　immunosensor　for　detection　of　carcinoembryonic　antigen　(CEA,　as　a　model　analyte)　in　clinical　immunoassays.　The　as-prepared　nanomaterials　composed　of　a　magnetic　mesoporous　NiCo2O4　nanosheet,　an　interlayer　of　Nafion/thionine　organic　molecules　and　a　nanogold　layer　show　good　adsorption　properties　for　the　attachment　of　horseradish　peroxidase-labeled　secondary　anti-CEA　antibody　(HRP-anti-CEA).　With　a　sandwich-type　immunoassay　format,　the　functional　bionanomaterials　present　good　analytical　properties　to　facilitate　and　modulate　the　way　it　was　integrated　onto　the　electrochemical　immunosensors,　and　allows　the　detection　of　CEA　at　a　concentration　as　low　as　0.5　pg/mL.　Significantly,　the　immunosensor　could　be　easily　regenerated　by　only　using　an　external　magnet　without　the　need　of　any　dissociated　reagents.　Importantly,　the　as-synthesized　magnetic　mesoporous　NiCo2O4　nanomaterials　could　be　further　extended　for　detection　of　other　biomarkers　or　biocompounds.