Shedding Light on the Dark Corners of MOF Thin Films: Growth and Structural Stability of ZIF-8 Layers Probed by Optical Waveguide Spectroscopy

ALLEGRETTO, JUAN ALEJANDRO; DOSTALEK, JAKUB; RAFTI, MATÍAS; MENGES, BERNHARD; AZZARONI, OMAR; KNOLL, WOLFGANG

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2018

1089-5639

Due to its many features and possible applications, metal-organic frameworks have attracted increasing attention in recent years. Within this type of materials, hydrophobic zeolitic imidazolate framework constituted of Zn2+ metal centers, coordinated by 2-methylimidazolate organic linkers (ZIF-8); has proved to be a highly versatile porous support compatible with diverse applications ranging from sensing platforms to electronics or energy-related devices. However, the study of a crucial parameter such as their structural stability towards exposure to different aqueous environments (relevant for a wide range of applications), remains only partially addressed and constitutes one of the main goals of the present work. By synthesizing mono- and multimode ZIF-8 optical waveguides for both optical waveguide and surface plasmon resonance spectroscopy, it was possible to characterize the ZIF-8 film growth, and its stability in different sensor-relevant liquid environments. Additionally, characterization of polyelectrolyte-modified films was explored, as it constitutes a relevant strategy in order to confer differential properties and enhanced stability to the films.