Fabrication of a Stable Cd-MOF as a Promising Luminescence Sensor for Selectively Distinguishing 3,4-Dichlorobenzamine and 3,5-Dichlorobenzamine in Real Urine and River Water Systems

In this paper, by the self-assembly of a symmetric tetracarboxylic ligand, H 4 mtptc (5′-methyl-[1,1′:3′,1″-triphenyl]-3,3″,5,5″-tetracarboxylic acid) and Cd(NO 3 ) 2 ·4H 2 O, a 2D Cd-based metal–organic framework, [Cd 2 (mtptc)(H 2 O) 4 (C 5 H 5 N) 2 ]·DMF·H 2 O ( Cd-MOF, compound 1 ) was developed successfully using a solvent thermal synthesis method. The X-ray diffraction experiment revealed that 1 featured outstanding acid–base stability and solvent stability. Moreover, considering the luminescence capacity and potential hazards of 3,4-dichlorobenzamine (3,4-DCA) and 3,4-dichlorobenzamine (3,5-DCA), luminescence-sensing measurements of 1 for 3,4-DCA/3,5-DCA were performed. The results indicate that 1 exhibited a distinguished potential for the selective detection of 3,4-DCA/3,5-DCA through luminescence quenching effects, with quenching constants ( K sv ) and limits of detection (LOD) of 2.72 × 10 4 M –1 and 0.71 μM for 3,4-DCA and 2.27 × 10 4 M –1 and 0.65 μM for 3,5-DCA in DMF-H 2 O solution. Besides, the exploration of the sensing capacities under practical conditions confirmed that the sensing performance of 1 in urine samples and real river water from the Tuhai River was comparable to that in DMF-H 2 O solution, further proving the promising potential of compound 1 as a reliable luminescence sensor for 3,4-DCA/3,5-DCA.