Superoxide　anion　(O2　center　dot-)　is　a　highly　reactive　oxygen　species　(ROS)　within　tumor　cells,　and　its　abnormal　concentrations　can　lead　to　various　diseases　such　as　cancer,　inflammation,　and　premature　aging　disorders.　Here,　we　obtained　a　series　of　bioluminescence　resonance　energy　transfer　(BRET)　systems　that　can　be　used　for　sensitive　and　specific　detection　of　O2　center　dot-　by　varying　the　type　and　reaction　time　of　quantum　dots　(QDs)　and　combining　them　with　different　concentrations　of　recombinant　aequorin.　Among　them,　the　recombinant　aequorin-conjugated　CdTe/CdSe　QDs　had　the　highest　conjugation　efficiency　as　the　Aeq-QD　BRET　sensor,　which　has　a　remarkable　energy　transfer　efficiency　of　35.6%　and　an　extremely　low　limit　of　4　nM　for　detecting　O2　center　dot-,　which　exceeds　traditional　chemiluminescence　detection　relying　on　coelenterazine.　The　applicability　of　this　sensor　for　assessing　tumor　oxidative　stress　levels　was　also　validated　in　diverse　cell　types　and　cancer　mice.　This　study　effectively　contributes　to　the　field　of　cancer　research　and　tumor　oxidative　stress　biology　based　on　O2　center　dot-　sensing.