Programmable nano-assembly of plasmonic materials for molecular interactions

Lead Research Organisation: University of Cambridge
Department Name: Physics

Abstract

The ability to look at small numbers of molecules in a sea of others has appealed to scientists for years. On the fundamental side we want to watch in real time how molecules undergo chemical reactions directly, how they explore the different ways they can come together, interact and eventually form a bond, and ideally we would like to influence this so that we can select just a single product of interest. We also want to understand how molecules react at surfaces since this forms the basis of catalysis in industrially relevant processes and is thus at the heart of almost every product in our lives. However, most scientific studies take place in precise conditions achieved in the laboratory, such as high vacuum, to select the cleanest possible conditions, but which look nothing like the real world applications they simulate. Hence most knowledge is empirical and pragmatically optimised.

We have been working on a completely new way to watch chemistry in an incredibly tiny test tube, itself a molecule. We use a barrel-shaped molecule called a 'CB' that can selectively suck in all sorts of different molecules. Recently, we have found a way to combine these barrel containers with tiny chunks of gold a few hundred atoms across, in such a way that shining light onto this gold-barrel mixture focuses and enhances the light waves into tiny volumes of space exactly where the molecules are located. By looking at the colours of the scattered light, we can work out what molecules are present and what they are doing, with enough sensitivity to resolve tiny numbers.

Our aim in this grant is to explore our promising start (that was seeded by EU funding). We aim to develop all sorts of ways to make useful structures that sense neurotransmitters from the brain, protein incompatibilities between mother and foetus, watch hydrogenation of molecules take place, find trace gases that are dangerous, and many others. At the same time we want to understand much more deeply and carefully how we can go further with such ideas, from controlling chemical reactions happening inside the container, to making captured molecules inside flex which can result in colour-changing switches. To make all this happen we take research groups spanning physics and chemistry and completely mix them up, so that they can work together on these very interdisciplinary aspects. We have found this works extremely well. We also involve a number of companies and potential end users (including the NHS) who know the real problems when trying to exploit these technologies in important areas including diagnostics, imaging and catalysis.

Planned Impact

We believe that a large range of potential impacts will emerge from this research programme:

Fundamental:
Understanding and controlling self-assembly on the sub-nm size scales has been sought for many years. We believe we have found a robust and significant approach, and that many further developments will emerge from our research. In particular demonstrating the influence of quantum transport within the optical domain is a real opportunity, as well as controlling electronic transport (since we create many identical junctions). We believe our approach will influence a wider research community to take up our ideas and develop them further in many directions.
Secondly, watching molecular interactions directly on this size scale opens up very many new possibilities in chemistry. Again we believe that there are prospects for others taking our advances in many directions. For instance exploring how conduction through molecules sequestered in the CBs between Au NPs offers a new route to molecular electronics. We have indicated in the proposal many promising areas around molecular sensing, and the potential control of chemical reactions, but we believe many more areas are possible. Because CBs are inert, and synthesised in high yield and volume, there are real practical applications that can follow.

Users:
The biomedical community would be strongly impacted for using this in real-time high-sensitivity biomolecule sensing. This is already evidenced by direct involvement of the NHS Raman Unit in this grant, as well as Renishaw Diagnostics who sell plasmonic diagnostics to this community (as well as the biomedical research and pharmaceutical sector). The ability for low-cost rapid medical screening would make a major impact to health.

The industrial and security communities would be impacted, for real-time sensing of molecules in a wide variety of scenarious. Evidence by direct involvement of BP in assembling sensors and catalyst probes, and DSTL for pathogen detection. The police have long sought a roadside test for cannabis (approaching us several times), while there are a host of applications in trace gas and contaminant detection.

Public:
We will all benefit from improved high-sensitivity, robust and quantitative sensing capabilities for molecular detection, leading to advances in mass-scale health screening, environmental sensing, security, and improved chemical products. More distant goals include advances in catalysis, including carbon sequestation. The public will also benefit from our novel ways to see quantum mechanics in action in ambient conditions, for instance at the science outreach events we plan.

More detailed impact consideration can be found in our Impact statement.

Publications

10 25 50
 
Description We are able to trap light in nanometre volumes by combining gold nanoparticles spaced by a new rigid molecule. Other molecules we trap in this space can then be found and characterised opening up new sensor technologies.
Exploitation Route We are working with a range of companies to explore these findings.
Sectors Chemicals,Environment,Healthcare,Pharmaceuticals and Medical Biotechnology

URL http://www.np.phy.cam.ac.uk/publications
 
Description We have been developing new technologies based on the nanoassembly using the CB molecule with Au nanoparticles. Currently we have been testing sensors for neurotransmitters in urine at clinical levels with this technology. We have also induced new chemical reactions in this nanoenvironment.
First Year Of Impact 2013
Sector Chemicals,Environment,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology
Impact Types Societal,Economic

 
Description EPSRC Programme grant (NOtCH)
Amount £6,013,126 (GBP)
Funding ID EP/L027151/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start  
 
Description ERC Advanced Investigator
Amount £1,666,666 (GBP)
Funding ID 320503 
Organisation European Research Council (ERC) 
Sector Public
Country European Union (EU)
Start  
 
Description Impact Accelaration Award EPSRC (CB sensing)
Amount £59,869 (GBP)
Funding ID X5:10877 CB sensing 
Organisation University of Cambridge 
Sector Academic/University
Country United Kingdom
Start 01/2016 
End 03/2017
 
Title Research data supporting "How Light is Emitted by Plasmonic Metals" 
Description The Data is collected and stored at the NanoPhotonics Centre, Cavendish Laboratory, University of Cambridge. This data was used to create the figures 1-4 in the associated publication "How light is emitted by plasmonic metals". 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Title Research data supporting "How ultra-narrow gap symmetries control plasmonic nanocavity modes: from cubes to spheres" 
Description Experimental and simulation data is collected at NanoPhootonics center, University of Cambridge. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Title Research data supporting "Strong-coupling of WSe2 in ultra-compact plasmonic nanocavities at room temperature" 
Description The Data was collected using costume build dark-field scattering microscopes and Photo emission setups. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Title Research data supporting [Mapping nanoscale hotspots with single-molecule emitters assembled into plasmonic nanocavities using DNA origami] 
Description Experimental and simulation data is collected at NanoPhotonics center, University of Cambridge. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
 
Description PhD award from NPL 
Organisation National Physical Laboratory
Country United Kingdom 
Sector Academic/University 
PI Contribution PhD studentship running in NanoPhotonics, on studying catalysis at the nanoscale.
Collaborator Contribution Support for joint supervision, and advanced equipment for experiments at NPL
Impact Just started
Start Year 2015
 
Description collaboration with DSTL 
Organisation Defence Science & Technology Laboratory (DSTL)
Country United Kingdom 
Sector Public 
PI Contribution joint research on UV SERS
Collaborator Contribution background on need and current technologies
Impact see publications on UV SERS
Start Year 2011
 
Description Naked Scientist interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact interview on our work recorded with Naked Scientist
Year(s) Of Engagement Activity 2015
 
Description Perse school science workshops 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact 9-10year olds, 2 workshops (Will, Laura, Anna, Lee)
Year(s) Of Engagement Activity 2015
 
Description Science Society talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact Talk for the Cambridge University Science Society
Year(s) Of Engagement Activity 2015
 
Description Stoner lecture, Leeds 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact JJB gave the Stoner lecture on translating research
Year(s) Of Engagement Activity 2017