Highly Selective Aqueous Phase Detection of Azinphos‐Methyl Pesticide in ppb Level Using a Cage‐Connected 3D MOF

A new metal‐organic framework (MOF) [Cd 2.5 (PDA)(tz) 3 ] {PDA= 1,4‐Phenylenediacetate and tz= 1,2,4‐triazolate}, 1 , has been synthesized by solvothermal reaction. The structure and morphology of 1 was systematically characterized by Powder X‐ray diffraction (PXRD), Single crystal X‐ray diffraction (SCXRD), Thermogravimetric analysis (TGA), Infrared spectroscopy (IR) and Field emission scanning electron microscopy (FESEM). Single crystal X‐ray data of 1 confirmed cage connected three‐dimensional structure with three different types of Cd 2+ ions (square pyramidal, trigonal antiprism and octahedral geometries). Photoluminescence study of 1 in aqueous medium showed emission at 290 nm upon excitation at 225 nm. This emissive property was used for the highly selective and sensitive detection of azinphos‐methyl pesticide in aqueous medium through luminescence quenching. Compound 1 is able to detect azinphos‐methyl with a detection limit of 16 ppb and its sensitivity remains unchanged in the presence of other pesticides.