The　redox　homeostasis　defense　mechanism　of　tumor　cells　is　one　of　the　prime　reasons　for　the　unsatisfactory　effect　of　photodynamic　therapy　(PDT).　So　far,　little　attention　has　been　paid　to　this　obstacle.　In　this　work,　we　reported　a　synthesizing　simple　yet　versatile　nanogel　(BCPS),　synthesized　by　cystamine　dihydrochloride　functionalized　sodium　carboxymethylcellulose　(CMC-SS),　bovine　serum　albumin,　and　Phycocyanobilin　self-assembly.　The　BCPS　reduced　the　levels　of　glutathione　molecules　by　reacting　with　glutathione,　thereby　interfering　with　intracellular　redox　homeostasis　and　enhancing　the　sensitivity　of　tumor　cells　to　PDT.　The　BCPS　was　shown　to　possess　excellent　serum　stability,　high　blood　compatibility,　low　toxic　side　effects,　and　higher　reactive　oxygen　species　(ROS)　utilization.　After　irradiation,　the　BCPS　could　significantly　increase　intracellular　ROS　level　by　approximately　1.6-fold　and　decrease　the　IC50　to　HeLa　cells　by　approximately　1.5-fold,　compared　to　the　pre-functional　drugs　BCP.　This　proposed　strategy,　based　on　increasing　the　utilization　rate　of　ROS　in　tumor　cells　is　promising　for　application　potentials　in　tumor　therapy.　©　2023　Elsevier　Ltd