Hydrolytically Stable Luminescent Cationic MOF for Selective Detection of Toxic Organic Arsenic in Water

Abstract

Drugs containing organic arsenic moiety are extensively utilized as food additives in the poultry industry, and release of these organic arsenics through poultry litter to natural water bodies can prove fatal and noxious to the ecosystem. Pertaining to this, sensitive detection of organic arsenic drugs in a selective manner from livestock waste water remains pivotal but indeed very challenging. In this work, we explored a cationic MOF, viz., iMOF-12C, as a fluorescence sensor toward precise recognition of organic arsenic molecules such as roxarsone (ROX) and nitarsone (NIT). Here we explore the potential of ionic MOFs for the first time toward recognition of organic arsenic drugs. iMOF-12C displayed excellent potency as a suitable sensory material toward selective detection of both ROX and NIT in water medium. The quenching efficiency of iMOF-12C toward ROX and NIT recognition was found to be 78 and 82%, respectively. The limit of detection (LOD) of iMOF-12C for ROX and NIT was calculated as 3.95 and 1.35 ppb, respectively, well below WHO’s safety limit. Further, for practical application, iMOF-12C-based mixed-matrix membranes (MMM) were casted, which showed excellent organic arsenic detection in water. The findings of this work highlight the potential of iMOF-12C toward real-time detection of organic arsenic molecules in water bodies.