title: Free-Standing, Nanopatterned Janus Membranes of Conducting Polymer-Virus Nanoparticle Arrays.
abstract: Nanostructured mesoscale materials find wide-ranging applications in medicine and energy. Top-down manufacturing schemes are limited by the smallest dimension accessible; therefore, we set out to study a bottom-up approach mimicking biological systems, which self-assemble into systems that orchestrate complex energy conversion functionalities. Inspired by nature, we turned toward protein-based nanoparticle structures formed by plant viruses, specifically the cowpea mosaic virus (CPMV). We report the formation of hierarchical CPMV nanoparticle assemblies on colloidal-patterned, conducting polymer arrays using a protocol combining colloidal lithography, electrochemical polymerization, and electrostatic adsorption. In this approach, a hexagonally close-packed array of polystyrene microspheres was assembled on a conductive electrode to function as the sacrificial colloidal template. A thin layer of conducting polypyrrole material was electrodeposited within the interstices of the colloidal microspheres and monitored in situ using electrochemical quartz crystal microbalance with dissipation (EC-QCM-D). Etching the template revealed an inverse opaline conducting polymer pattern capable of forming strong electrostatic interactions with CPMV and therefore enabling immobilization of CPMV on the surface. The CPMV-polymer films were characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Furthermore, molecular probe diffusion experiments revealed selective ion transport properties as a function of the presence of the CPMV nanoparticles on the surface. Lastly, by utilizing its electromechanical behavior, the polymer/protein membrane was electrochemically released as a free-standing film, which can potentially be used for developing high surface area cargo delivery systems, stimuli-responsive plasmonic devices, and chemical and biological sensors.
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Brylee David B
authors.initials: BD
authors.lastname: Tiu
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Sicily B
authors.initials: SB
authors.lastname: Tiu
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Wen
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Patricia
authors.initials: P
authors.lastname: Lam
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Nicole F
authors.initials: NF
authors.lastname: Steinmetz
authors.affiliation: Department of Macromolecular Science and Engineering, ‡Department of Biomedical Engineering, §Department of Radiology, ∥Department of Materials Science and Engineering, and ⊥Case Comprehensive Cancer Center, Case Western Reserve University , Cleveland, Ohio 44106, United States.
authors.forename: Rigoberto C
authors.initials: RC
authors.lastname: Advincula
mesh_terms: D017798:Comovirus; D053758:Nanoparticles; D011108:Polymers; D058525:Quartz Crystal Microbalance Techniques
chemical_list: D011108:Polymers