Abstract: Embodiments of the synthesis, radiolabeling and biological applications of an activatable tracer that undergoes intramolecular cyclization and aggregation upon activation by cleavage of a blocking moiety are provided. The probes of the disclosure allow for target-controlled self-assembly of small molecules in living subjects for imaging and drug delivery. The aggregated nanoprobes of the disclosure may be detectable optically, by PET detection, magnetic resonance imaging, and the like depending on the detectable reporter attached to the nanoprobe.

Abstract: The compositions of the present disclosure provide novel fluorogenic probes for use in the specific imaging and detection of mycobacteria species, and in particular ?-lactam-antibiotic resistant. Specificity for mycobacteria is conferred on these probes by incorporating a moiety that specifically targets the unique trapping mechanism of the DprE1 found in in mycobacteria. Accordingly, only Mycobacteria species that express both a ?-lactamase and DprE1 enable both the activation of the caged fluorescent probe, and the affixing of the released fluorescent probes to the bacteria cells through the functioning reduction-covalent binding mechanism. Advantageously, such a probe is able, at its most sensitive, to allow single mycobacterium detection.

Abstract: The compositions of the present disclosure provide novel fluorogenic probes for use in the specific imaging and detection of mycobacteria species, and in particular ?-lactam-antibiotic resistant. Specificity for mycobacteria is conferred on these probes by incorporating a moiety that specifically targets the unique trapping mechanism of the DprE1 found in in mycobacteria. Accordingly, only Mycobacteria species that express both a ?-lactamase and DprE1 enable both the activation of the caged fluorescent probe, and the affixing of the released fluorescent probes to the bacteria cells through the functioning reduction-covalent binding mechanism. Advantageously, such a probe is able, at its most sensitive, to allow single mycobacterium detection.