Background:　Ferroptosis,　as　a　novel　form　of　cell　death,　is　becoming　one　of　the　hot　topics　in　cancer　treatment　research.　It　differs　from　necrosis　and　autophagy　in　that　it　involves　the　accumulation　of　lipid　peroxides　and　is　triggered　by　iron　dependency.　Recent　studies　have　suggested　that　this　mechanism　may　alter　the　viscosity　or　structure　of　lipid　droplets　(LDs).　The　relationship　between　LDs　viscosity　and　ferroptosis　remains　an　active　area　of　research　with　limited　reports　at　present.　Additionally,　there　is　a　lack　of　effective　anticancer　drugs　targeting　the　ferroptosis　pathway　to　promote　ferroptosis　in　tumour　cells.　Therefore,　the　development　of　tools　to　detect　viscosity　changes　during　ferroptosis　and　targeted　therapeutic　strategies　is　of　great　significance.　Results:　By　coupling　1,3-indandione　with　naphthalimide,　including　decamethylamine　as　a　LDs　recognition　group,　we　designed　and　synthesized　an　environmental　fluorescent　probe　that　induces　intramolecular　charge　transfer　(TICT)　effects.　Notably,　the　diffusion　and　transport　of　intracellular　substances　may　be　affected　in　highly　viscous　environments.　Under　such　conditions,　intracellular　iron　ions　may　accumulate,　leading　to　peroxide　production　and　cellular　damage,　which　can　trigger　ferroptosis.　Therefore,　WD-1　achieved　excellent　in　situ　bioimaging　of　LDs　targeting　and　its　viscosity　during　ferroptosis　in　HeLa　cells　and　zebrafish.　Furthermore,　it　was　observed　that　WD-1　effectively　differentiated　between　malignant　and　normal　cells　during　this　process,　highlighting　its　potential　significance　in　distinguishing　cellular　states.　In　addition,　we　used　the　antitumour　drug　paclitaxel　to　study　ferroptosis　in　cancer　cells.　These　findings　not　only　provide　an　excellent　tool　for　the　development　of　the　ferroptosis　response,　but　also　are　crucial　for　understanding　the　biological　properties　of　LDs　during　the　ferroptosis　response.　Significance　and　novelty:　Based　on　a　powerful　tool　of　fluorescent　probe　with　in　vivo　bioimaging,　we　developed　WD-1　to　track　the　impact　of　paclitaxel　on　the　process　of　ferroptosis　in　living　cells.　Therefore,　we　preliminarily　believe　that　paclitaxel　may　affect　the　occurrence　of　ferroptosis　and　control　apoptosis　in　cancer　cells.　These　findings　not　only　serve　as　an　exceptional　tool　for　advancing　our　understanding　of　the　ferroptosis　response,　but　furthermore　play　a　vital　role　in　comprehending　the　biological　characteristics　of　LDs　in　relation　to　ferroptosis.　©　2024　Elsevier　B.V.