Small molecules with circularly polarized luminescence (CPL) are especially valuable in solution-based applications, like chiroptical probes for effective sensing. However, such application has not been well explored due in part to hard introduction of appropriate triggerable fluorophores. Herein, we report an easily post-modifiable CPL-active scaffold (4) and further propose a feasible strategy to construct chiroptical probes for sensing hypochlorous acid. Helically chiral 4 with a 4, 4′-bicarbazole scaffold exhibits a large Stokes shift up to 142 nm and g value of 0.9 × 10. Through facile construction of phenothiazine moiety on 4, red-emitting compound 5 was obtained in high yield (85.3%), showing distinct optical and chiroptical responses towards hypochlorous acid with good liner relationships and CPL sign blue-shifting of 120 nm in vitro. The probe is also applied to detect endogenous hypochlorous acid in living macrophages and can serve as a CPL sensor. Taking 5 as an application example, we envision that CPL-enabling scaffold 4 could find broad use in the design of more chiroptical probes.