A new pyromellitic acid and 3,5-bis(benzoimidazo-1-ly)pyridine based Zn(ii)-MOF as prospective turn-off–on sensor for tetracycline

Abstract

Metal–organic frameworks (MOFs) constitute an assorted class of multi-dimensional materials that offer the potential to serve as luminescent sensors for the sensitive and selective detection of antibiotics in wastewater. Herein, a new Zn(II)-based MOF with the formula [Zn(PMA)_0.5(bbp)·H₂O·DMA] (1) (bbp = 3,5-bis(benzoimidazo-1-ly)pyridine; PMA = pyromellitic acid) was synthesized by a solvothermal method and characterized. Crystallographic analysis reveals that MOF 1 possesses a 4,4-connected net with the Schläfli symbol {3²·4·5²·6}₂{3²·4²·5²}. The fabricated MOF exhibited luminescent property and was employed as a luminescent sensor to sensitively and selectively detect tetracycline (TCY) antibiotic amongst thiamphenicol (THI), 2-methyl-4-chlorophenoxyacetic acid (MCPA), tetracycline (TCY), sulfamethoxazole (SMT), thiabendazole (TBZ), tinidazole (TDZ), sulfadiazine (SDZ), chloramphenicol (CAP), metamitron (MMT), and dinotefuran (DTF). Further, restoration of the emissive response of TCY@1 was achieved by adding salicylic acid with a concomitant bathochromic shift in the emissive response. The possible sensing mechanism and restoration of emissive response were assessed with the aid of theoretical calculations.