Here,　the　inner　filter　effect　(IFE)　was　applied　to　construct　a　“turn　off”　mode　up-conversion　fluorescence　and　colorimetric　dual-reading　detection　platform　consisting　of　the　chromogenic　substance　p-phenylenediamine　(PPD)　and　NaYF4:Yb/Er@NaYF4　core–shell　up-conversion　nanoparticles　(UCNPs)　for　the　detection　of　glucose　and　hydrogen　peroxide　(H2O2)　with　high　sensitivity　and　selectivity.　In　this　strategy,　hydrogen　peroxide　is　produced　in　the　process　of　glucose　oxidation　by　catalyzing　glucose　oxidase　(GOx).　PPD　is　oxidized　by　H2O2　under　the　action　of　horseradish　peroxidase　(HRP),　resulting　in　the　transformation　into　its　oxidation　product　PPDox,　whose　absorption　peak　coincides　with　the　emission　peak　of　UCNP　at　540　nm,　which　can　significantly　quench　the　fluorescence　of　UCNP.　The　quenching　efficiency　is　related　to　PPDox　production,　so　the　relationship　between　the　glucose　content　and　the　fluorescence　changes　of　UCNP　can　be　established　to　realize　the　sensitive　detection　of　glucose.　UCNPs　modified　by　–COOH　and　the　oxidation　product　of　PPD　were　negatively　charged,　which　increased　the　distance　between　donor　and　recipient　due　to　electrostatic　repulsion.　It　was　not　conducive　to　the　occurrence　of　distance-dependent　fluorescence　resonance　energy　transfer　(FRET),　which　was　also　verified　by　fluorescence　lifetime　test.　Under　the　optimal　experimental　conditions,　the　linear　ranges　of　hydrogen　peroxide　and　glucose　were　2.5　∼　50　and　5　∼　80　μmol/L　with　the　detection　limit　(LOD)　of　0.32　and　0.83　μmol/L,　respectively,　which　were　lower　than　of　some　reported　approaches.　Furthermore,　the　system　could　be　applied　to　the　detection　of　glucose　in　actual　serum　sample　and　the　results　were　consistency　of　commercial　glucose　meters　which　indicated　that　the　protocol　was　reliable　and　potential　applications　for　clinical　diagnosis.　©　2022　Elsevier　B.V.