In　this　work,　photoactivated　oxidase　mimetics　was　prepared　by　copolymerizing　dicyandiamide　with　barbituric　acid　(BA)　and　characterized　by　X-ray　diffraction　pattern,　Fourier　transformed　infrared　spectrum,　X-ray　photoelectron　spectroscopy,　transmission　electron　microscopy,　photoluminescence　spectrum,　diffuse　reflectance　spectrum.　Experimental　results　and　density　functional　theory　calculation　indicated　that　the　substitution　of　nitrogen　atoms　by　carbon　atoms　in　tri-s-triazine　structure　due　to　the　copolymerization　of　BA　enhanced　visible　light　absorption　and　weakened　the　barrier　of　photocarrier　transfer.　In　the　presence　of　visible　light　and　oxygen,　3,　3′,　5,　5′-tetramethylbenzidine　was　oxidized　under　the　catalysis　of　photoactivated　oxidase　mimetics　to　produce　a　green　colored　product,　which　could　be　reduced　by　glutathione　(GSH).　Therefore,　a　facile　method　based　on　the　photoactivated　oxidase　mimetic　has　been　developed　for　colorimetric　detection　of　GSH.　The　linear　range　for　GSH　was　ranged　from　2.0　to　50.0　μmol　L−1　(R2　=　0.998)　with　the　detection　limit　of　1.4　μmol　L−1.　The　proposed　method　was　applied　to　detect　the　cellular　GSH　with　satisfactory　results.　©　2019　Elsevier　B.V.