Virus Nanowires: Virus as Scaffolds for Inorganic Nanostructures
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Angela Belcher Massachusetts Institute of Technology Virus nanowires Viruses as scaffolds for inorganic nanostructures Stijn Goossens Supervisor: Prof. Dr. G. ten Brinke Stijn Goossens – Viruses as scaffolds for nanostructures Introduction • Biomimicing • Advances in molecular biology: bind specific inorganic materials like semiconductors and metals • Researchers at MIT: engineer viruses with specific binding properties Stijn Goossens – Viruses as scaffolds for nanostructures Biomolecules as glue • MIT: genetically engineered virus: M13 bacteriophage • Proteins on viral capsid show binding with specific metals/semiconductors Stijn Goossens – Viruses as scaffolds for nanostructures M13 bacteriophage • DNA (circular single stranded) encapsulated in a protein coat • 880 nm • Major coat proteins, minor coat proteins at ends http://belcher10.mit.edu Stijn Goossens – Viruses as scaffolds for nanostructures Combinatorial screening • Engineering = selecting • Select M13 with right protein on surface • Genetic engineering → Display library ~109 different M13 viruses • Selection by application to substrate Stijn Goossens – Viruses as scaffolds for nanostructures Combinatorial screening http://belcher10.mit.edu Stijn Goossens – Viruses as scaffolds for nanostructures Minor coat particle nucleation • Peptide inserts at minor coat protein • ZnS nanocrystals (quantumdot) nucleation • Nanocrystals - ~4nm in size - zinc blende phase - preferred orientation - size and phase dependent on peptide • Similar results for CdS Science 296, 892 (2002); J Mater Chem, 13, 2414 (2003) Stijn Goossens – Viruses as scaffolds for nanostructures Major coat particle nucleation • ZnS nanocrystals with preferred orientation PNAS 100 6946 (2003) Stijn Goossens – Viruses as scaffolds for nanostructures Virus nanowires • Annealing at 400 – 500 °C: – Removal organic materials – Crystalline nanowires Science 303, 213 (2004) Stijn Goossens – Viruses as scaffolds for nanostructures Supramolecular self assembly • Viruses as buildingblocks for supramolecular structures Acta Materialia 51, 5867 (2003) Stijn Goossens – Viruses as scaffolds for nanostructures Application: Li-ion battery • Full use of biotemplating • Co3O4 nanowire electrode – 600-750 mA*h/g • Heterowires: Au & Co3O4 – 30% more capacity • Electrolyte: flexible polymer substrate Science 312, 885 (2006) Stijn Goossens – Viruses as scaffolds for nanostructures Conclusion & Outlook • Ease of genetic modification → growth and assembly nanomaterials: – Quantumdots – Nanowires – Supramolecular structures • Future research: – Much more materials possible – More control on ordering behaviour Stijn Goossens – Viruses as scaffolds for nanostructures