A Smart Sensing Method for Object Identification Using Circularly Polarized Luminescence from Coordination‐Driven Self‐Assembly

The potential use of circularly polarized luminescence for object identification in a sensor application is demonstrated. New luminescence probes using pyrene derivatives as sensor luminophores were developed. (R,R)‐Im 2 Py and (S,S)‐Im 2 Py contain two chiral imidazole moieties at 1,6‐positions through ethynyl spacers (angle between spacers ca. 180°). The probe molecules spontaneously self‐assemble into chiral stacks (P or M helicity) upon coordination to metal ions with tetrahedral coordination (Zn 2+ ). The chiral probes display neither circular dichroism (CD) nor circularly polarized luminescence (CPL) without metal ions. However, (R,R)‐Im 2 Py and (S,S)‐Im 2 Py exhibit intense chiroptical activity (CD and CPL) upon self‐assembly with Zn 2+ ions. (R,R)‐Im 2 Py and (S,S)‐Im 2 Py with chemical stimuli‐responsibility allow sensing using the CPL signal as detection output, enabling us to discriminate between a signal from the target analyte and that from non‐target species.