Periodic 3-D nanoparticle arrays by protein crystallization

Lead Research Organisation: University of Bristol
Department Name: Physics


Very small particles with diameters of only a few nanometres (a nanometre is a unit of length 1000 000 000 times smaller than a metre) can have properties quite different from bulk materials. If particles of this size are assembled to form a periodic array, that is one in which a simple arrangement of particles is repeated many times, electrical and magnetic interactions between the particles can further change the properties. This is what makes periodic arrays of nanometre-sized particles, known as nanoparticles for short, interesting.This project is to develop a new way of making 3-dimensional periodic arrays of nanoparticles, with novel and useful magnetic and optical properties. Many ways have been found to make 2-dimensional periodic arrays of nanoparticles, but making a truly 3-dimensional array, more than a few nanoparticles thick, is much more difficult. The approach we propose promises to be faster and more flexible than the current alternative, which is a purely chemical technique known as colloidal crystallization. Our method introduces elements of biology as well as chemistry, because we will synthesize nanoparticles inside proteins, then crystallize the protein. Since a protein crystal is a periodic array of molecules, and each molecule contains a nanoparticle, the result will be the desired 3-dimensional periodic array of nanoparticles.We will start by using the protein ferritin to make nanoparticles. The ferritin molecule is shaped like a hollow sphere and cells use it to store iron. We will synthesize magnetic metal and oxide nanoparticles for magnetic studies, and other metal nanoparticles for optical studies. We will find the best conditions for growing large crystals of ferritin with nanoparticles inside, and use very sensitive techniques such as scanning probe microscopy and dynamic light scattering to study the very earliest stages of array growth. We will change the symmetry of our 3-dimensional periodic arrays by changing the crystallization conditions and we will also study other proteins, including Dps, which has a similar structure to ferritin, but is used to protect DNA.We will measure the magnetic properties of our nanoparticle arrays at different temperatures and compare the results with computer simulations. This will help us gain a deeper understanding of how the magnetic fields of all the individual particles interact to determine the magnetic behaviour of the array as a whole. Understanding magnetic interactions is important for developing new materials for magnetic data recording as well as being of interest in itself.We will also measure how light is transmitted through and reflected from 3-dimensional periodic arrays of silver, gold and alloy nanoparticles. The fact that the period of the array will be much smaller than the wavelength of light makes these systems particularly interesting. Their study will contribute to the future development of exotic optical devices such as perfect lenses or shields that can make an object invisible.


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Correia Carreira S (2016) Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells. in Journal of visualized experiments : JoVE

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Correia M (2016) Magnetic relaxation of nanoparticles with cubic and uniaxial anisotropies in Journal of Physics: Conference Series

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Eloi JC (2014) Effective energy barrier distributions for random and aligned magnetic nanoparticles. in Journal of physics. Condensed matter : an Institute of Physics journal

Description This research has led to a deeper understanding of how interactions between magnetic nanoparticles affect their properties when they are combined together into an array, as well as providing new insight into how the magnetic anisotropy of individual particles affects their magnetization after heating and cooling cycles in different magnetic fields. Both are likely to be important in future applications of magnetic nanoparticles, for example in medicine. We also discovered a new method of using magnetic nanoparticles to probe the environment in freeze-concentrated solutions, something that is likely to prove relevant to the food and pharaceutical industries.
Exploitation Route The new method we discovered for probing freeze-concentrated solutions is being taken forward through research funded by the Leverhulme Trust
Sectors Agriculture, Food and Drink,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Healthcare,Pharmaceuticals and Medical Biotechnology

Description Our findings have formed the basis for a European Commission Framework 7 project, which could ultimately lead to new methods of processing information based on spin-waves in meta-materials. The project has already made a contribution to strengthening international research links.
First Year Of Impact 2009
Sector Digital/Communication/Information Technologies (including Software)
Impact Types Societal

Description International Joint Project:Protein-based colloidal crystal nanowires
Amount £11,600 (GBP)
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 08/2010 
End 09/2012
Description Magnonics - Mastering magnons in magnetic meta-materials
Amount € 664,657 (EUR)
Funding ID CP-FP 228673-2 MAGNONICS 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 07/2009 
End 08/2012
Description Research Project Grant
Amount £173,483 (GBP)
Funding ID RPG-2014-180 
Organisation The Leverhulme Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2015 
End 04/2018
Description Cuiaba 
Organisation Federal University of Mato Grosso
Country Brazil 
Sector Public 
PI Contribution Dr Edson Chagas from UFMG spent a year working with me as a visiting researcher in 2013-14.
Collaborator Contribution Sample preparation, magnetic measurements
Impact One paper, reported elsewhere
Start Year 2013
Description NIMP 
Organisation National Institute of Materials Physics Magurele-Bucharest
Country Romania 
Sector Public 
PI Contribution Preparation of proteins for subsequent growth of colloidal crystal nanowires
Collaborator Contribution Preparation of templates
Impact Publication in preparation
Start Year 2010
Description Theoretical study of magnetic interactions 
Organisation Federal University of Santa Catarina
Country Brazil 
Sector Academic/University 
PI Contribution Experimental work
Collaborator Contribution Prof Wagner Figueiredo and a student who visited Bristol, Mr Marcos Correia, carried out calculations for joint publications
Impact Publications, listed elsewhere
Start Year 2009