The fluorogenic tweezers NPDM was designed and easily obtained in two steps (Scheme S1). The intermediate NS was synthesized by the Duff reaction according to the previous work; after that the NPDM was successfully synthesized via the Schiff-base condensation reaction between the NS and DAMN, which was also characterized using 1 H NMR, C NMR, and HRMS (high-resolution mass spectrometry) (Fig. -S5, ESI).