"Turn-on" and ratiometric detection of carboxylesterases using acetyl-based fluorescent strategies for bacterial applications.

Carboxylesterases (CEs) are involved in the biotransformation of numerous drugs, environmental toxicants, and carcinogens containing ester groups. Abnormal CEs levels are associated with various diseases, and as such they are widely studied in cells. CEs are also characteristic biomarkers for assisting in the detection of certain strains of bacteria and are involved in important biological processes. Herein, we used two probes including an indene-chalcone-based fluorescent probe which displays green "turn-on" fluorescence response, and a merocyanine-based ratiometric probe to detect CEs, as well as detect and image S. aureus and their chronic biofilms using an acetate ester as recognition group. • Two fluorescent indene-chalcone (turn on) and merocyanine (ratiometric) probes for carboxylesterases were evaluated for bacterial applications. • The probes exhibit rapid response, good optical performance, high selectivity, and high sensitivity. • The probes facilitate the detection and imaging of carboxylesterases in a range of S. aureus species, and clinical biofilms. [ABSTRACT FROM AUTHOR]