2,4,6-Trinitrophenol　(TNP)　is　widely　used　in　our　daily　life;　however,　excessive　use　of　TNP　can　lead　to　a　large　number　of　diseases.　Therefore,　it　is　necessary　to　find　an　effective　method　to　detect　TNP.　Herein,　the　rapid　fluorescence　quenching　by　TNP　was　developed　for　the　fluorometric　determination　of　TNP　in　aqueous　medium　based　on　the　internal　filter　effect.　Nitrogen-sulfur–codoped　carbon　nanoparticles　(N,S-CNPs),　synthesized　by　a　one-pot　solvothermal　method　with　the　precursors　of　l-cysteine　and　citric　acid,　were　applied　for　the　determination　of　TNP　as　a　fluorescent　probe.　The　excitation　peak　center　of　N,S-CNPs　and　the　emission　peak　center　are　340 nm　and　423 nm,　respectively.　The　probe　can　be　used　in　a　variety　of　conditions　to　detect　TNP　due　to　its　relatively　stable　properties.　Meanwhile,　it　has　a　fast　response　time　(＜　1 min),　wide　linear　response　range　(0.1–40 μM),　and　low　detection　limit　(43.0 nM).　This　probe　still　has　excellent　selectivity　and　high　sensitivity.　The　method　was　also　used　to　detect　standard　water　samples　with　a　satisfactory　recovery　rate,　and　it　will　be　used　in　the　application　of　pollutants　and　clinical　diseases.　[Figure　not　available:　see　fulltext.].　©　2020,　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.