Development of Eu-based metal-organic frameworks (MOFs) for luminescence sensing and entrapping of arsenate ion

Abstract A new type of Eu-based metal organic framework (Eu-MOF) characterized with ability of arsenate ion luminescence sensing and entrapping was constructed via solvothermal method based on the optimization of the organic ligand. The Eu-MOF aqueous dispersion sample displayed arsenate-triggered augment in luminescence emission intensity with appreciable contrast and detection sensitivity with limit of detection down to 17.8 nM toward arsenate ion, which is less than one-fourth of the upper limit concentration of arsenic in drinking water that the World Health Organization (WHO) set for public health, 72 nM. Additionally, the excellent recognition specificity Eu-MOF toward arsenate species over various potential interfering anions and cations was also confirmed. The rapid adsorption ability of Eu-MOF nanostructures toward arsenate in aqueous milieu that plausibly originated from its nature of chemical adsorption and the adsorption feature conforming to the Langmuir model was also verified. The advantages that Eu-MOF nanostructure displays in terms of high sensitivity and recognition specificity in luminescence sensing of arsenate ion and the desired arsenate entrapping ability in aqueous milieu is expected to impart it potential for sensing and entrapping trace amount of arsenate in water in practical applications.