Nanoelectronic Detection of Acetone with MIL-53(Al)−NH₂ Metal–Organic Framework on Single-Walled Carbon Nanotubes

A new composite material has been synthesized by incorporating an amine-functionalized MIL-53 (Al) metal-organic framework (MOF) and single-walled carbon nanotubes (SWCNT) under hydrothermal conditions. This hybrid material combines the porosity of the MOF with the electrical conductivity of SWCNT. The preservation of MIL-53(Al)-NH₂ MOF structure and morphology in the composite with SWCNT was verified by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller surface area analysis. A characteristic current-voltage (<i>I</i>-<i>V</i>) curve showed the electrical conductivity of this composite and gave a linear response in the chemiresistive sensor with increasing concentrations of acetone. The MIL-53(Al)-NH₂/SWCNT composite also displayed fluorescence quenching tendencies across various acetone concentrations, likely attributable to the impact of guest molecules influencing the framework. An alternative approach utilizing layer-by-layer sensor device fabrication was employed for growing this MOF on carbon nanotubes directly onto a silicon chip, demonstrating its potential for versatile on-chip-sensing applications.