1：Experimental Design and Method Selection:

The study involved synthesizing a Eu(III) MOF using solvothermal methods, characterizing its structure, and evaluating its luminescence properties for sensing nitro explosives, particularly picric acid. Theoretical models included Stern-Volmer analysis for quenching constants.

2：Sample Selection and Data Sources:

The ligand 9H-carbazole-2,7-dicarboxylic acid was synthesized based on literature, and other chemicals were commercially obtained. Samples included EuL crystals and suspensions in DMF for testing.

3：List of Experimental Equipment and Materials:

Equipment included Perkin-Elmer 240C analyzer for elemental analysis, PerkinElmer FTIR spectrometer for IR spectra, NETZSCH STA2500 for TGA, Bruker D8 advanced diffractometer for PXRD, SHIMADZU UV-3600 spectrophotometer for UV-Vis, RF-5301PC spectrofluorophotometer for photoluminescence, Edinburgh FLS920P spectrophotometer for fluorescence lifetimes, and ASAP 2020M for gas sorption. Materials included Eu(NO3)3?6H2O, DMF, water, glacial acetic acid, and various nitro explosives.

4：Experimental Procedures and Operational Workflow:

Synthesis involved heating a mixture in a Teflon-lined autoclave at 120°C for 2 days. Characterization included elemental analysis, IR, TGA, PXRD, UV-Vis, NMR, photoluminescence, and lifetime measurements. Sensing experiments involved adding nitro explosives to EuL-DMF suspensions and measuring fluorescence quenching.

5：Data Analysis Methods:

Data were analyzed using Stern-Volmer equations for quenching constants, with linear regression for sensitivity. Detection limits were calculated based on titration data.