Enzyme‐Activated, Chemiluminescent Siderophore‐Dioxetane Probes Enable the Selective and Highly Sensitive Detection of Bacterial Pathogens

Abstract The sensitive detection of bacterial infections is a prerequisite for their successful treatment. The use of a chemiluminescent readout was so far hampered by an insufficient probe enrichment at the pathogens. We coupled siderophore moieties, that harness the unique iron transport system of bacteria, with enzyme‐activatable dioxetanes and obtained seven trifunctional probes with high signal‐to‐background ratios (S/B=426‐859). Conjugates with efficient iron transport capability into bacteria were identified through a growth recovery assay. All ESKAPE pathogens were labelled brightly by desferrioxamine conjugates, while catechols were weaker due to self‐quenching. Bacteria could also be detected inside lung epithelial cells. The best probe 8 detected 9.1×10 3 CFU mL −1 of S. aureus and 5.0×10 4 CFU mL −1 of P. aeruginosa , while the analogous fluorescent probe 10 was 205–305fold less sensitive. This qualifies siderophore dioxetane probes for the selective and sensitive detection of bacteria.