A luminescent nanocrystal metal organic framework for chemosensing of nitro group containing organophosphate pesticides

Abstract

A luminescent nanocrystal metal–organic framework (NMOF1) of [Cd(atc)(H₂O)₂]_nhas been synthesized by the reaction of Cd(II) ions with the sodium salt of H₂atc (2-aminoterephthalic acid) in aqueous solution. The obtained fluorescent porous material has been characterized by X-ray diffraction, transmission electron microscopy, confocal microscopy, UV-visible spectroscopy, photoluminescence spectroscopy and surface area analysis. The synthesized NMOF1 exhibits reasonably good fluorescence characteristics (excitation wavelength = 340 nm, emission wavelength = 436 nm). The potential of the above Cd(II) based nanocrystal metal–organic framework (NMOF1) for the sensing of the nitroaromatic-containing organophosphate pesticides (nitro OPs) parathion, methyl parathion, paraoxon and fenitrothion is demonstrated. It has been possible to detect the above four OPs separately in the concentration range of 1–500 ppb. The detection limit of the proposed method for all the said OPs is 1 ppb. Interestingly, their mixture also shows the above characteristic data. The proposed method for the sensing of nitro OPs is also selective towards other OPs such as malathion, dichlorvos and monocrotophos.