Nanozymes-based　optical　sensors　are　widely　used　in　the　field　of　disease　diagnosis,　but　most　of　the　metal-based　nanomaterials　with　peroxidase-like　would　not　only　require　the　addition　of　unstable　and　slightly　toxic　hydrogen　peroxide　but　also　often　be　affected　by　their　own　oxidase-like　activity　leading　to　the　problems　such　as　poor　reproducibility　and　environmental　pollution.　Moreover,　single-mode　biosensors　are　subject　to　signal　instability,　which　can　lead　to　false-positive　or　false-negative　results.　Hence,　we　synthesized　two　three-component　covalent　organic　frameworks　(COFs)　with　the　oxidase-like　and　ascorbate　oxidase-like　activities　using　benzo[1,2-b:3,4-b＇:5,6-b＇＇]trithiophene-2,5,8-tricarboxaldehyde　(BTT)　and　1,3,5-tris(4-formylphenyl)benzene　(TFPB)　as　the　nodes,　and　1,4-diaminobenzene　(PA)　and　4,4-diaminodiphenyl　(BD)　as　the　linker　units.　Both　three-component　COFs　had　narrow　band　gaps　(2.16　eV　and　2.27　eV),　excellent　electron　transport　properties,　and　high　enzyme-like　specific　activities　(4.32　U　mg−1　and　1.82　U　mg−1).　Based　on　these,　a　colorimetric　and　ratiometric　fluorescence　dual-mode　cascade　catalytic　platform　was　developed　to　detect　the　activity　of　alkaline　phosphatase　(ALP),　a　marker　for　diseases　such　as　liver　and　bone.　The　constructed　analytical　methods　had　a　detection　limit　as　low　as　0.10　U　L−1　and　were　successfully　used　to　detect　ALP　levels　in　human　serum.　This　work　also　provides　a　new　idea　for　developing　an　efficient　multimodal　detection　and　evaluation　platform　using　nanozymes　based　on　novel　COFs.　©　2024　Elsevier　B.V.