A 1,8-naphthalimide-based lysosome-targeting dual-analyte fluorescent probe for the detection of pH and palladium in biological samples

Fluorescent probes containing 1,8-naphthalimide dyes have been used to detect biomolecules in the environmental and biological fields. However, most of the probes only exhibit single fluorescent output to one analyte, making them insufficient for detection of more analytes. Herein, we developed a novel 1,8-naphthalimide-based lysosome-targeting dual-analyte sensitive fluorescent probe (DPPP) for the detection of pH and palladium (Pd-0) using two different emissive channels. The probe showed high selectivity, large Stokes shifts (Delta lambda >= 100 nm) and enhanced response to pH, with blue emission at 485 nm via a morpholine group, and responsive to Pd-0 concentration, with yellow emission at 545 nm via an allylcarbamate group. The effect of DPPP was successfully observed for sensitive visualizing pH and Pd-0 concentration in the lysosome of HeLa cells and zebrafish using fluorescence microscopy. This work provides guidance for the design of dual-analyte fluorescent probes.

Automated summary

A novel 1,8-naphthalimide-based lysosome-targeting dual-analyte sensitive fluorescent probe (DPPP) was developed for the detection of pH and palladium (Pd-0), with high sensitivity and selectivity. The probe demonstrated enhanced response to pH and different emissive channels for pH and Pd-0 concentration detection.