Volume 90 Issue 20 | p. 39 | Concentrates
Issue Date: May 14, 2012

Graphene-Amyloid Combo

Materials consisting of alternating layers of graphene and amyloid protein fibrils function as shape-shifting biosensors
Department: Science & Technology
News Channels: Analytical SCENE, Biological SCENE, Materials SCENE, Nano SCENE
Keywords: graphene, nanocomposite, amyloid
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SHAPE MEMORY
This graphene-amyloid film shape-shifts when changing from dry (left) to wet (right) and back again; it rises about 20 mm.
Credit: Courtesy of Raffaele Mezzenga
This photo shows a nanocomposite with a graphene-to-amyloid ratio of 1:8 reversibly changing shape under different moisture levels: dry (left), wet (middle), dry a second time (right). It rises about 20 mm.
 
SHAPE MEMORY
This graphene-amyloid film shape-shifts when changing from dry (left) to wet (right) and back again; it rises about 20 mm.
Credit: Courtesy of Raffaele Mezzenga

Nanocomposites made of alternating layers of graphene and amyloid protein fibrils could improve graphene-based materials for biological applications, scientists at ETH Zurich report (Nat. Nanotechnol., DOI: 10.1038/nnano.2012.62). The fibrils stabilize graphene in water while preserving its two-dimensional carbon sheet organization, according to Raffaele Mezzenga and coworkers. The team made the nanocomposites by suspending graphene oxide in solution with different amounts of β-lactoglobulin and then reducing the graphene oxide to graphene. The nanocomposites’ conductivity decreased with increasing amyloid content, but even the least conductive hybrid was more conductive than pure graphene oxide films. By using vacuum filtration, the researchers obtained rigid, freestanding films sturdy enough to cut with scissors. The materials reversibly changed shape in response to changes in humidity, opening new possibilities for humidity sensors and moisture-activated switches, Mezzenga says. The team used the materials to make biosensors that measure enzyme activity.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

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