We have developed QMP-SOs, a new class of superoxide-specific probes capable of proximity labelling and chemoproteomic profiling of proteins associated with superoxide redox biology. By coupling QMP-SOs with quantitative proteomics using tandem mass tag, we have established a chemoproteomics platform, QMP-SO-TMT. This enables us to profile proteins associated with superoxide biology in HepG2 cells treated with menadione, which induces mitochondrial superoxide production.