skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: 3D Visualization of Proteins within Metal–Organic Frameworks via Ferritin‐Enabled Electron Microscopy
Abstract Electron tomography holds great promise as a tool for investigating the 3D morphologies and internal structures of metal‐organic framework‐based protein biocomposites (protein@MOFs). Understanding the 3D spatial arrangement of proteins within protein@MOFs is paramount for developing synthetic methods to control their spatial localization and distribution patterns within the biocomposite crystals. In this study, the naturally occurring iron oxide mineral core of the protein horse spleen ferritin (Fn) is leveraged as a contrast agent to directly observe individual proteins once encapsulated into MOFs by electron microscopy techniques. This methodology couples scanning electron microscopy, transmission electron microscopy, and electron tomography to garner detailed 2D and 3D structural interpretations of where proteins spatially lie in Fn@MOF crystals, addressing the significant gaps in understanding how synthetic conditions relate to overall protein spatial localization and aggregation. These findings collectively reveal that adjusting the ligand‐to‐metal ratios, protein concentration, and the use of denaturing agents alters how proteins are arranged, localized, and aggregated within MOF crystals.  more » « less
Award ID(s):
2102033
PAR ID:
10543041
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
Advanced Functional Materials
Volume:
34
Issue:
13
ISSN:
1616-301X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; (, Angewandte Chemie International Edition)
    Abstract Metal–organic frameworks (MOFs) with mobile charges have attracted significant attention due to their potential applications in photoelectric devices, chemical resistance sensors, and catalysis. However, fundamental understanding of the charge transport pathway within the framework and the key properties that determine the performance of conductive MOFs in photoelectric devices remain underexplored. Herein, we report the mechanisms of photoinduced charge transport and electron dynamics in the conductive 2D M−HHTP (M=Cu, Zn or Cu/Zn mixed; HHTP=2,3,6,7,10,11‐hexahydroxytriphenylene) MOFs and their correlation with photoconductivity using the combination of time‐resolved terahertz spectroscopy, optical transient absorption spectroscopy, X‐ray transient absorption spectroscopy, and density functional theory (DFT) calculations. We identify the through‐space hole transport mechanism through the interlayer sheet π–π interaction, where photoinduced hole state resides in HHTP ligand and electronic state is localized at the metal center. Moreover, the photoconductivity of the Cu−HHTP MOF is found to be 65.5 S m−1, which represents the record high photoconductivity for porous MOF materials based on catecholate ligands. 
    more » « less
  2. ; ; ; (, Frontiers in Chemistry)
    null (Ed.)
    A new electrically conducting 3D metal-organic framework (MOF) with a unique architecture was synthesized using 1,2,4,5-tetrakis-(4-carboxyphenyl)benzene (TCPB) a redox-active cis -dipyridyl-tetrathiafulvalene ( Z -DPTTF) ligand. While TCPB formed Zn 2 (COO) 4 secondary building units (SBUs), instead of connecting the Zn 2 -paddlewheel SBUs located in different planes and forming a traditional pillared paddlewheel MOF, the U-shaped Z -DPTTF ligands bridged the neighboring SBUs formed by the same TCPB ligand like a sine-curve along the b axis that created a new sine -MOF architecture. The pristine sine -MOF displayed an intrinsic electrical conductivity of 1 × 10 −8  S/m, which surged to 5 × 10 −7  S/m after I 2 doping due to partial oxidation of electron rich Z -DPTTF ligands that raised the charge-carrier concentration inside the framework. However, the conductivities of the pristine and I 2 -treated sine -MOFs were modest possibly because of large spatial distances between the ligands that prevented π-donor/acceptor charge-transfer interactions needed for effective through-space charge movement in 3D MOFs that lack through coordination-bond charge transport pathways. 
    more » « less
  3. ; ; ; ; ; ; ; ; (, Journal of Materials Chemistry A)
    Recently, metal–organic framework (MOF)-based polymeric substrates show promising performance in many engineering and technology fields. However, a commonly known drawback of MOF/polymer composites is MOF crystal encapsulation and reduced surface area. This work reports a facile and gentle strategy to produce self-supported MOF predominant hollow fiber mats. A wide range of hollow MOFs including MIL-53(Al)–NH 2 , Al-PMOF, and ZIF-8 are successfully fabricated by our synthetic method. The synthetic strategy combines atomic layer deposition (ALD) of metal oxides onto polymer fibers and subsequent selective removal of polymer components followed by conversion of remaining hollow metal oxides into freestanding MOF predominant hollow fiber structures. The hollow MOFs show boosted surface area, superb porosity, and excellent pore accessibility, and exhibit a significantly improved performance in CO 2 adsorption (3.30 mmol g −1 ), CO 2 /N 2 separation selectivity (24.9 and 21.2 for 15/85 and 50/50 CO 2 /N 2 mixtures), and catalytic removal of HCHO (complete oxidation of 150 ppm within 60 min). 
    more » « less
  4. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Materials)
    Abstract Large‐scale synthesis of van der Waals (vdW) metal–organic framework (MOF) nanosheets with controlled crystallinity and interlayer coupling strength is one of the bottlenecks in 2D materials that has limited its successful transition to large‐scale applications. Here, scalable synthesis of mBDC (m = Zn and Cu) 2D MOFs at large scales through a biphase method is demonstrated. The results show replacing water molecules with pyridine eliminates hydrogen bond formation at metal cluster sites. This prohibits tight coupling across adjacent MOF layers and sustains controllable 2D vdW MOF growth. It is further shown that control over the growth speed, crystallinity, and thickness can be achieved by addition of a controlled amount of triethylamine and formic acid to achieve highly crystalline vdW MOF nanosheets with extraordinarily high aspect ratio. The described synthesis route can easily be scaled up for large‐scale production either by deposition onto desired substrates or in crystalline layered powder form. Owing to its large lateral size, vdW nature, and high crystallinity, it is possible to perform atomic force microscopy, Kelvin probe force microscopy, and Raman measurements on the 2D MOFs. The results not only establish their vibrational properties and layer‐dependent responses but also show striking differences from other 2D inorganic materials. 
    more » « less
  5. ; ; ; ; (, Small Structures)
    One of the key challenges in separation science is the lack of precise ion separation methods and mechanistic understanding crucial for efficiently recovering critical materials from complex aqueous matrices. Herein, first‐principles electronic structure calculations and in situ Raman spectroscopy are studied to elucidate the factors governing ion discrimination in an adsorptive membrane specifically designed for transition metal ion separation. Density functional theory calculations and in situ Raman data jointly reveal the thermodynamically favorable binding preferences and detailed adsorption mechanisms for competing ions. How membrane binding preferences correlate with the electronic properties of ligands is explored, such as orbital hybridization and electron localization. The findings underscore the importance of the phenolate group in oxime ligands for achieving high selectivity among competing transition metal ions. In‐depth understanding on which specific atomistic site within the microenvironment of metal‐ligand binding pockets governs the ion discrimination behaviors of the host will build a solid foundation to guide the rational design of next‐generation materials for precision separation essential for energy technologies and environment remediation. In tandem, synthetic controllability is demonstrated to transform 3D micrometer‐scale crystals to a 2D crystalline selective layer in membranes, paving the way for more precise and sustainable advances in separation science. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email