{Reference Type}: Journal Article {Title}: β-Carbonyl sulfonium enables cysteine-specific bioconjugation for activity-based protein profiling in live cells. {Author}: Wan C;Yang D;Guo X;Zhang T;Ruan Z;Dai C;Xing Y;Yin F;Wang R;Li Z; {Journal}: Chem Commun (Camb) {Volume}: 60 {Issue}: 27 {Year}: 2024 Mar 28 {Factor}: 6.065 {DOI}: 10.1039/d4cc00295d {Abstract}: Chemical labeling methods for proteins are highly researched. Herein, we introduced β-carbonyl sulfonium compounds for selective cysteine modification in proteins within biological systems. Structural tuning led to sulfonium-based probes with high reactivity and selectivity. These probes show excellent biocompatibility, cell uptake, and specificity towards cysteine profiling in live cells.