The Cooperativity of Fe3 O4 and Metal-Organic Framework as Multifunctional Nanocomposites for Laser Desorption Ionization Process

A novel and facile strategy in developing a water stable magnetic metal-organic framework nanocomposite (Fe3O4@MOF) is herein reported, in which a Keggin polyoxometalate, phosphotungstic acid (HPW), was encapsulated within the MOF framework via one-pot synthesis method. The combination of HPW-embedded MOF and Fe3O4 endowed the composite with high surface area, strong UV absorption, good hydrophilicity, and enhanced water stability. With these unique properties, the Fe3O4@MOF embedded HPW served as adsorbent as well as matrix for SALDI-MS (surface-assisted laser desorption ionization mass spectrometry) analysis of polar and non-polar compounds. The synergistic effect of Fe3O4 and MOF showed an interference-free background at low mass region than the pristine MOF or Fe3O4 counterparts. This simple approach can be used as new platform in developing magnetic MOF composites without the time consuming and labor-intensive preparation.