Synthetic and biological nanoparticles combined to produce new metamaterials
January 9, 2013
Aalto University scientists have organized synthetic and biological building blocks in a single structure — combining virus particles (and other protein cages) with inorganic nanoparticles to form crystalline layer structures, or superlattices.
The research aims to develop hierarchically structured nanomaterials with tunable optical, magnetic, electronic and catalytic properties. Such nanomaterials are important for applications in sensing, optics, electronics and drug delivery.
By generating biohybrid 3D superlattices of nanoparticles and proteins, “the versatility of synthetic nanoparticles and the highly controlled assembly properties of biomolecules can be combined,” explains Dr Mauri Kostiainen of Aalto University Department of Applied Physics, who led the research.
For example, they showed that virus or ferritin protein cages can be used to guide the assembly of RNA molecules or iron oxide nanoparticles into superlattices, formed through tunable electrostatic interactions with charged gold nanoparticles.
“The gold nanoparticles and viruses adopt a special kind of crystal structure that doesn’t correspond to any known atomic or molecular crystal structure and it has previously not been observed with nano-sized particles,” said Kostiainen.
Kostiainen and his colleagues also discovered magnetic self-assemblies of ferritin protein cages and gold nanoparticles. These magnetic assemblies can control spin-spin relaxation times of surrounding protons in water by enhancing the spin dephasing, allowing them to provide contrast enhancement in magnetic resonance imaging (MRI).
The Academy of Finland funded the study.