Nanomolar Level Fluorogenic Detection of Cyanide with an Amide Functionalized Zirconium Metal‐Organic Framework and Its Application in Real‐World Cyanide Monitoring

Abstract

This work contains synthesis of a di-amide linker based Zr(IV) metal-organic framework (MOF, 1) and its characterization with by PXRD, elemental analysis, FE-SEM, EDX and FT-IR analysis and application for the detection of toxic cyanide in aqueous medium. Furthermore, the physicochemical stability of the sensor was judged by the thermogravimetric analysis (TGA) and PXRD analysis. TGA curve of 1 displayed that the thermal stability of the probe was up to 230 °C. The MOF material was stable in sensing medium and in wide pH range (pH = 2-8) which were confirmed by PXRD analysis of the recovered samples. The surface area (BET) of this porous sensor was 672 m 2 /g with a pore volume of 0.36 cm 3 /g at p/p o = 0.5. Guest free form of the MOF material (1') displayed its high efficiency for the fluorescence recognition of cyanide (CN À ) with an extraordinary limit of detection of 76.4 nM in aqueous medium. Comparable recognition time (10 min) as the other available chemosensors of CN À ion and sensing of CN À using easily portable paper strips make this probe an extraordinary chemosensor for CN À ions. Together with paper strip based sensing, detection of CN À in apple seeds, various real water samples and wide ranges of pH solutions are the special features of the probe. The abstraction of amide proton by CN À ion favors "turnon" sensing, which was revealed by 1 H-NMR titration. This sensor of cyanide can also be used as luminescent switch due to its reversible nature of sensing.

Regulating water decontamination and food safety by a reusable, nano-sized MOF@cotton@chitosan composite through nanomolar detection of the drug nitroxinil and organoarsenic feed additive p-arsanilic acid

“…50 In the case of 1 , a strong peak at 1654 cm −1 appeared. 51 This is because of the stretching vibrations of the carbonyl functionality of the guest DMF. However, this particular peak was not present in the case of 1′ , which indicated the complete absence of the solvent molecules in the activated compound.…”

A Cd(ii)-organic framework as a highly sensitive and rapid fluorometric sensor for ascorbic acid in aqueous medium

“…Metal-organic frameworks (MOFs) contain metal nodes and organic linkers as their structural components. 8,[17][18][19] The exceptional features of MOFs such as 3D rigid network, pores inside the framework, organic-inorganic hybrid system and insoluble nature in common solvents make them suitable for definite applications like gas purification, 20 catalysis, 21 drug delivery, 22 fluorescence-based sensing [23][24][25] etc. Luminescence active MOFs (LMOFs) are well-established materials in the scientific community and still developing due to the necessity of real-life requirements.…”