Ultralarge Single-Layer Porous Protein Nanosheet for Precise Nanosize Separation

Abstract

Highly permeable and precisely size-selective membranes are the subject of continuous pursuit for energy-efficient separation of fine chemicals. However, challenges remain in the fabrication of an ultrathin selective layer with homogeneous pores, in particular, with the pore sizes in the 1-10 nm range. We report the design of a free-standing porous nanosheet assembled with a single layer of proteins. Tobacco mosaic virus mutant (TMVm), a cylinder-shaped protein containing an inner pore of 4 nm in diameter, was cross-linked via a Cu-catalyzed disulfide-bond-forming reaction along the 2D orientation. By such a design, ultralarge single-layer TMVm nanosheets extending over tens of micrometers in width and with well-defined nanopores were successfully developed. A ∼40 nm thick ultrafiltration membrane laminated by the single-layer TMVm nanosheets through simple vacuum filtration accomplished the precise separation of ∼4 nm sized substances. Meanwhile, the membrane exhibited water permeance up to ∼7000 L m h bar, which is an order of magnitude improvement compared with traditional ultrafiltration membranes with a similar rejection profile.

Precise Size‐Selective Sieving of Nanoparticles Using a Highly Oriented Two‐Dimensional Supramolecular Polymer

“…Alternatively, the bottom‐up self‐assembly provides a facile solution for the membrane fabrication because supramolecular materials are generally solution‐processable . To date, 2D porous nanosheets (or polymers) formed by noncovalent interactions have been extensively developed, particularly toward the precise nanoscale separation . Very recently, we reported a novel trinuclear complex ( Pt 3 (OTf) 3 ; Figure a), consisting of three cationic alkynylplatinum(II) terpyridine moieties and carrying six dodecyl side chains that self‐assembles into a honeycomb‐like 2D supramolecular polymer (2D SP Pt3 ; Supporting Information, Figure S1a), which is noncovalently bridged by the dimeric units of adjacent platinum(II) terpyridine complexes .…”

“…Semiconductor quantum dots (QDs) are one of the most efficient luminescent NPs that have been employed as bioimaging probes and emitting materials for displays . Because their emission wavelengths are strongly dependent on their sizes and diameters, the selective isolation of monodisperse QDs is very important, with separation of QDs through filtration readily visualized by monitoring their luminescence changes . To test the capability of SPM in separating QDs of different sizes and hence different luminescence colors, 1‐thioglycerol‐capped CdTe‐QDs with various sizes and color‐tunable luminescence were synthesized .…”

Protein Nanopore Membranes Prepared by a Simple Langmuir–Schaefer Approach

“…It should also be mentioned that membrane preparation based on lipid or block copolymer bilayers is solely suited for TPs and, so far, the incorporation of other interesting biological nanopores, such as virus-like particles derived from tobacco mosaic virus (TMV), [25] into stable membranes has required rather cumbersome procedures. [26,27] To bypass these limitations, we pursue different strategies of membrane fabrication that provide covalent stabilization and dense arrangement of protein nanopores. Previously, we crosslinked ferritin-polymer conjugates to ultrathin membranes and formed nanopores by denaturation of the protein.…”

Tracking and Recovery of Metal Desorption from Organized Films of Polyguanamine Derivatives having Cyclic Moieties

“…Those materials which possess structural spaces and/or voids are being investigated for the ability of the spaces to be manipulated for specialized functionality beyond that which has been conventionally considered [2,3] . Such innovation is applicable to energy conversion materials, [4] materials which store, transport, separate, and convert chemical substances, [5–8] molecular recognition materials, [9] and medical, [10] structural, [11] and electronic materials [12] . By following trends in materialization and processing, researchers are able to anticipate the imminent need for these materials and approach their development by conducting generalized studies on the controlled synthesis of molecular spaces and voids [13] and their potential functionalities ascertained by groundbreaking theoretical calculations [14,15] …”