Development　of　metal-free　nanozymes　has　raised　concern　for　their　extensive　applications　in　photocatalysis　and　sensing　fields.　As　novel　metal-free　nanomaterials,　covalent　organic　frameworks　(COFs)　have　engendered　intense　interest　in　the　construction　of　nanozymes　due　to　their　structural　controllability　and　molecular　functionality.　The　formation　of　the　molecular　arrangement　by　embedding　orderly　donor-acceptors　(D-A)　linked　in　the　framework　topology　to　modulate　material　properties　for　highly　efficient　enzyme　mimicking　activity　is　of　importance　but　challenging.　Here,　a　strong　D-A　type　of　COF　was　designed　and　synthesized　by　integrating　electron　donor　units　(pyrene)　and　electron　acceptor　units　(phenanthroline),　named　Py-PD　COF.　Using　experiments　and　theoretical　calculations,　the　introduction　of　a　phenanthroline　ring　endowed　the　Py-PD　COF　with　a　narrowed　band　gap,　and　efficient　charge　transfer　and　separation.　Further,　the　Py-PD　COF　exhibited　a　superior　light-responsive　oxidase-mimicking　characteristic　under　visible　light　irradiation,　which　could　catalyze　the　oxidation　of　3,3′,5,5-tetramethylbenzidine　(TMB)　and　give　the　corresponding　evolution　of　color.　The　nanoenzymatic　activity　of　the　Py-PD　COF　was　light-regulated,　which　offers　a　fascinating　advantage　because　of　its　high　efficiency　and　spatial　controllability.　Based　on　previously　mentioned　characteristics,　an　＇on-off＇　sensing　platform　for　the　colorimetric　analysis　of　isoniazid　(INH)　could　be　constructed　with　a　good　linear　relationship　(2-100　μM)　and　a　low　limit　of　detection　(1.26　μM).　This　research　shows　that　not　only　is　Py-PD　COF　an　environmentally　friendly　compound　for　the　colorimetric　detection　of　INH,　but　it　is　also　capable　of　providing　the　interesting　D-A　type　COF-based　material　for　designing　an　excellent　nanozyme.　©　2024　The　Royal　Society　of　Chemistry.