Abstract
Defect engineering proves to be a highly effective approach for introducing additional open metal sites and porosity into metal-organic frameworks (MOFs), thereby enhancing their gas storage, separation, and chemical catalysis capabilities. However, characterizing defective MOFs, which often exhibit nonuniform pores, presents a significant challenge. While probe molecules have been widely utilized to explore the physical and chemical properties of MOF pores, their application has predominantly been limited to gas- or vapor-phase molecules. In this study, we present a novel approach by employing a size-selective fluorescent protein probe to characterize macroporous defects induced by tartaric acid in a zirconium-based MOF, NU-1000. The spatial visualization of defects using a hemoglobin-based fluorescent probe allows for the identification of distinct structural weak points and defect formation mechanisms in NU-1000 crystallites prepared by various methods. In addition to confirming findings from conventional MOF characterization methods, such as gas sorption isotherms and powdered X-ray diffraction analysis, the hemoglobin-based protein probe unveils structural nuances overlooked by many traditional characterization techniques.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1396-1403 |
| Number of pages | 8 |
| Journal | ACS Materials Letters |
| Volume | 6 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2024 |
Funding
We thank the financial support from CBC U.S. Army Contracting Command (W52P1J-21-9-3023) and Defense Threat Reduction Agency (DTRA1-19-1-0007). F.S. gratefully acknowledges support from the Ryan Fellowship and the International Institute for Nanotechnology at Northwestern University. NMR and crystallography are performed at the IMSERC facility, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633), IIN, and Northwestern University. SEM measurements made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-2025633); the MRSEC program (NSF DMR-1121262) at the Materials Research Center; the International Institute for Nanotechnology (IIN); and the State of Illinois, through the IIN. Confocal microscopy was performed at the Biological Imaging Facility at Northwestern University (RRID:SCR_017767), supported by the Chemistry for Life Processes Institute, the NU Office for Research, the Department of Molecular Biosciences, and the Rice Foundation.
ASJC Scopus subject areas
- General Chemical Engineering
- Biomedical Engineering
- General Materials Science