To confirm the underlying mechanism for this quenching process, PL lifetimes for these chiral POPs in MeOH were also measured in absence or presence of PA. As shown in Figure , PL decay profiles revealed that the emission lifetimes of PRBT had gradually decreased from 0.77 ns in absence of PA to 0.63 ns in presence of PA (Figure and). Therefore, we deduced that the quenching mechanism for these chiral POPs toward PA sensing was probably a dynamic quenching process without the formation of a stable non-fluorescent species between the chiral POPs with quencher molecules. Based on the "Stern-Volmer" formalism, the quenching constant K SV for PRBT and PSBT was calculated. The K SV for PA and PRBT was determined to be approximately 2.18 × 10 4 M -1 (Table ), whereas the quenching constant for other analogues was one order lower (Figure ). Therefore, the luminescent chiral POPs had proven their potential as a promising sensor for explosive molecules with PA as the model compound.