Devising robust hydrophobic MOFs and its membrane for ultra-sensitive aqueous phase detection of antibiotics and toxic nitro-explosives and adsorption of TNP

Antibiotics and nitro-explosives constitute a major sector of the chemical pollutants contaminating the water in industrial area, hence sensitive detection of these pernicious organic pollutants is a daunting task this era. Herein, we have rationally devised two hydrophobic robust (water and pH =2–12 stable) luminescent microporous Zn2+ based metal-organic frameworks, MOF-1 and MOF-2 through strategic selection of two π-conjugated trigonal spacers and an organic linker with pendant -CF3 moieties rendering hydrophobicity. These MOFs (especially MOF-1 which is moderately porous compared to the non-porous MOF-2) exhibit excellent detection of antibiotics (NZF) and hazardous nitro-explosive (TNP) in aqueous phase instantly through luminescent turn-off quenching with record setting lowest detection limits (LOD: 17.2 ppb and 48.1 ppb for TNP in MOF-1a and MOF-2a respectively; 27.5 ppb (lowest) and 109.7 ppb for NZF in MOF-1a and 2a respectively). The luminescent quenching is dictated by the synchronous occurrence of both resonance energy transfer and photoinduced electron transfer mechanisms, validated with DFT calculations. Additionally, MOF-1a adsorbs TNP from an aqueous solution with excellent uptake value (843.41 mg/g). A mixed matrix membrane (MOF-1a@PVDF) is fabricated for instant detection and/or adsorption of NZF and TNP, authenticating its real time applicability for treating the wastewater liberated from industries.