Ancillary ligand enabled structural and fluorescence diversity in metal-organic frameworks: application for the ultra-sensitive detection of nitrofuran antibiotics

Fabrication of high-performance sensory materials for the ultra-sensitive detection of antibiotics in water is of significant importance for community health and environmental quality. Herein, two Zn( ii )-based metal-organic frameworks, {[Zn 3 (cbbi) 2 (bpe)(H 2 O) 6 ]·2H 2 O} n ( FCS-4 ) and {[Zn 4 (OH) 2 (cbbi) 2 (bpee)(H 2 O) 4 ]·2H 2 O} n ( FCS-5 ), were prepared hydrothermally and employed as chemosensors for the ultra-sensitive detection of nitrofuran antibiotics. Interestingly, different spacers and flexibility in the nitrogen-donor ancillary ligands resulted in different topological structures and fluorescence properties. FCS-5 exhibited much better sensitivity for nitrofurazone and nitrofurantoin detection, with limits of detection (LOD) of 0.22 and 0.15 ppm, respectively. Furthermore, mechanism exploration indicated that photon-induced electron transfer plays a key role in the ultra-sensitive detection of nitrofuran antibiotics. Fabrication and engineering of two new MOFs with flexible dipyridyl ligands for the fluorescence turn-off detection of antibiotics.