Herein,　a　vinylene-linked　covalent　organic　framework　(TMT-BPDA-COF)　was　prepared　via　the　Aldol　condensation　of　2,4,6-trimethyl-1,3,5-triazine　(TMT)　and　4,4＇-biphenyl　dimethyl　formaldehyde　(BPDA).　TMT-BPDA-COF　displayed　high　crystallinity　and　thermal　stability,　and　robust　chemical　stability　in　strong　acid,　strong　base　and　common　organic　solvents.　TMT-BPDA-COF　nanosheets　emitted　strong　yellow　fluorescence　with　the　quantum　yield　of　14.9%　and　showed　fast　reversible　response　toward　pH　with　a　wide　range　(pH　0.0　∼　14.0)　based　on　the　intramolecular　charge　transfer　effect.　Furthermore,　portable　fluorescent　sensors　were　prepared　by　incorporated　TMT-BPDA-COF　nanosheets　into　agarose　gel　and　cellulose　acetate　butyrate　(CAB),　respectively.　TMT-BPDA-COF　gel　showed　a　wide　pH　response　range　over　pH　0.0　∼　14.0　with　a　linear　range　of　pH　4.0　∼　14.0.　TMT-BPDA-COF　CAB　film　exhibited　high　sensitivity　for　sensing　of　NH3　gas　with　a　limit　of　detection　of　1.6　ppb.　TMT-BPDA-COF　agarose　gel　and　CAB　film　also　exhibited　good　reversibility　and　reproducibility　in　response　to　pH　and　NH3　gas,　respectively.　We　expect　TMT-BPDA-COF-based　sensors,　which　feature　fast　response,　high　sensitivity,　wide　response　range,　good　reproducibility　and　reversibility,　can　apply　to　detect　pH　and　NH3　gas　in　the　field　of　environment　and　industry.　©　2023　Elsevier　B.V.