Template‐Directed Synthesis of Porous and Protective Core–Shell Bionanoparticles

Abstract

Metal-organic frameworks (MOFs) are promising high surface area coordination polymers with tunable pore structures and functionality;h owever,al acko fg ood sizea nd morphological control over the as-prepared MOFs has persisted as an issue in their application. Herein, we show how arobust protein template,tobacco mosaic virus (TMV), can be used to regulate the sizea nd shape of as-fabricated MOF materials.W ew ere able to obtain discrete rod-shaped TMV@MOF core-shell hybrids with good uniformity,a nd their diameters could be tuned by adjusting the synthetic conditions,w hichc an also significantly impact the stability of the core-shell composite.More interestingly,the virus particle underneath the MOF shell can be chemically modified using astandardbioconjugation reaction, showing mass transportation within the MOF shell.Metal-organic frameworks (MOFs) are af amily of microporous crystalline materials with high specific surface areas and extended porosities,w hich have attained al evel of preeminence because of their synthetic tunability.AMOF is constructed by coordinating rigid organic struts to ametal ion or cluster node to form ac rystalline material with ad efined pore structure,p ore size,a nd chemical composition. [1] The seemingly infinite combination of metal nodes and organic struts has enabled highly tunable design strategies for specific needs, [2] such as gas storage, [3] sensing, [4] catalysis, [5] energy, [6] and in biomedical applications. [7] An issue arising in many of these applications,h owever, has been the difficulty in controlling the crystallite morphology,w hich typically yields bulk MOF powders with relatively large crystal size,random shape,a nd poor monodispersity.T here is an articulated [8] interest in controlling the morphology of MOF crystallites because of the need for nanometer scale uniformity in biomedical and optoelectronics applications.T he synthetic strategies so far employed to regulate the size and morphology of MOF crystals have generally involved the addition of metal-binding reagents such as ligands,s urfactants,o rp olymers with chelating functional moieties. [9] Although these strategies afford regulation of size,t he as-obtained MOF particles are typically several hundred nanometers in size. More recently,M OF core-shell nanoparticles in the 100 nm range with good monodispersity have emerged, [10] though control over shape is not always high, resulting in irregular spheres or cubes.Virus nanoparticles offer alevel of control unavailable in synthetic systems as the surface chemistry can be altered by either chemical or genetic manipulation. [11] We selected the tobacco mosaic virus (TMV), at ubular viral particle that contains 2130 identical coat proteins self-assembled around as ingle strand of RNA. Because it is 300 nm long and only 18 nm wide,t he anisotropy of the virus has made it an attractive target for applications in photonics, [12] light harvesting solar arrays, [13] and MRI contrast agents. [14] TMV is also attractive because it can be isolated in gr...

Ultrarobust Biochips with Metal–Organic Framework Coating for Point-of-Care Diagnosis

“…Similar phenomenon was observed by Gassensmith and co-workers, where they found that the ZIF-8 film (with a same (4:1) molar ratio of 2-methylimidazole and zinc acetate) was unstable after the sample was removed from mother liquor solution containing the ZIF-8 precursors. 53 Based on this finding, we adjusted the molar ratio of 2-methylimidazole and zinc acetate to 40:1, and observed ~65 nm red shift in the LSPR wavelength (higher than ~55 nm red shift using 4:1 ratio, Figure 5B and 5C) due to the formation of thicker film (~28 nm thickness measured by AFM scratch) (Figure S4D). More importantly, such coatings did not disintegrate after immersing the biochips into DMF or protease solution (Figure 5E and 5F), and thereby the preservation efficacy in both cases was greatly improved (Figure 5A, red bars).…”

A Convenient and Versatile Amino‐Acid‐Boosted Biomimetic Strategy for the Nondestructive Encapsulation of Biomacromolecules within Metal–Organic Frameworks

“…[10] Unfortunately,t he surface charge and chemistry of the protein strongly determined its ability to be encapsulated into the MOFs:o nly those with al ow surface electrostatic potential were capable of concentrating the metal cations and inducing the encapsulation process. [10] Unfortunately,t he surface charge and chemistry of the protein strongly determined its ability to be encapsulated into the MOFs:o nly those with al ow surface electrostatic potential were capable of concentrating the metal cations and inducing the encapsulation process.…”

“…Encasing ap rotein within aM OF that possessed significantly smaller pore dimensions than the biomacromolecule was recently achieved via am ild de novo approach, such as biomimetic mineralization. [10] Unfortunately,t he surface charge and chemistry of the protein strongly determined its ability to be encapsulated into the MOFs:o nly those with al ow surface electrostatic potential were capable of concentrating the metal cations and inducing the encapsulation process. [11] Moreover,there are cases in which it takes along time (several days) to induce MOF formation.…”

Two‐Dimensional Metal‐Organic Framework Nanosheets: A Rapidly Growing Class of Versatile Nanomaterials for Gas Separation, MALDI‐TOF Matrix and Biomimetic Applications

“…After the synthesis, it is crucial to clearly demonstrate the structure of 2D MOF nanosheets. Although the crystal structures of MOFs were usually solved by the precise measurements with the single crystal X‐ray diffraction technique or the combined agreement between simulation and refinement with powder X‐ray diffraction (XRD), there are still no decisive single technique to determine the structure of 2D MOF nanosheets . The combination of multiple techniques was normally employed for the characterization.…”

“…Although the crystal structures of MOFs were usuallys olved by the precise measurements with the single crystal X-ray diffractiont echnique or the combined agreement between simulation and refinement with powderX -ray diffraction( XRD), there are still no decisives ingle technique to determine the structure of 2D MOF nanosheets. [45,65,66] www.chemeurj.org 2018 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim whose X-ray diffraction patternsh ave to agree with their simulated ones. [57,67] Then the morphology of the nanosheets can be characterized by transmission electron microscope (TEM), scanninge lectron microscope (SEM), and atomicf orce microscope (AFM).…”