Photodynamic　therapy　is　an　emerging　tumor　therapy　that　kills　tumor　cells　by　activating　reactive　oxygen　species　(ROS)　produced　by　photosensitizers.　Mitochondria,　as　an　important　organelle,　are　the　main　generator　of　cellular　ROS.　Therefore,　the　development　of　photosensitizers　capable　of　targeting　mitochondria　could　significantly　enhance　the　efficacy　of　photodynamic　therapy.　In　this　study,　two　novel　ruthenium(ii)　complexes,　Ru-1　and　Ru-2,　were　designed　and　synthesized,　both　of　which　were　functionalized　with　α,β-unsaturated　ketones　for　sensing　of　glutathione　(GSH).　The　crystal　structures　of　the　two　complexes　were　determined　and　they　exhibited　good　recognition　of　GSH　by　off-on　luminescence　signals.　The　complex　Ru-2　containing　aromatic　naphthalene　can　enter　the　cells　and　react　with　GSH　to　generate　a　strong　luminescence　signal　that　can　be　used　to　monitor　intracellular　GSH　levels　through　imaging.　Ru-2　also　has　an　excellent　mitochondrial　localization　ability　with　a　Pearson＇s　coefficient　of　0.95,　which　demonstrates　that　it　can　efficiently　target　the　mitochondria　of　tumor　cells　to　enhance　the　effectiveness　of　photodynamic　therapy　as　a　photosensitizer.　©　2024　The　Royal　Society　of　Chemistry.