Interactions, Interfaces and Sensing

Research in this Unit involves measurement, technique and instrument development and computation, with applications right across chemistry and with strong links to biosciences, chemical engineering, computer science, materials science, medicine and physics.

We have particular expertise and interests in analytical science; bio-nanotechnology; biophysical chemistry; catalysis; charge transfer and transport; clusters and nanoparticles; electrochemistry; environmental chemistry; fluorescence; magnetic resonance spectroscopy and imaging; optical sensors; scanning probe microscopy; self-assembly; simulation and modelling; single molecule imaging; soft matter; solvation effects; surface and interfacial chemistry; synchrotron-based characterisation; theoretical chemistry.

Research unit leader

Areas of interest

Biophysical chemistry; catalysis; clusters and nanoparticles; computational and theoretical chemistry; self-assembly; simulation and modelling; surface and interfacial chemistry

Representative publication: Structures and Energy Landscapes of Hydrated Sulfate Clusters

Lewis C. Smeeton, James D. Farrell, Mark T. Oakley, David J. Wales and Roy L. Johnston
J. Chem. Theory Comput., 11 (2015) 2377-2384

Johnston_paper

This paper reports a global optimization and energy landscape mapping study of hydrated sulfate ions, SO42–(H2O)n, in the size range 3 ≤ n ≤ 50. The clusters are modelled using a rigid-body empirical potential and optimized using basin-hopping Monte Carlo in conjunction with hydrogen-bond cycle inversions to explore hydrogen bond topologies. Experimental studies have shown that dangling hydroxyl groups are present on the surfaces of pure water clusters for all sizes, but are absent in hydrated sulfate clusters up to n ≈ 43. Our global optimization results agree with this observation, with dangling hydroxyl groups absent from the low-lying minima of small clusters, but competitive in larger clusters. 

Research unit members

Areas of interest

Analytical chemistry; bio-nanotechnology; biophysical chemistry; catalysis; charge transfer and transport; clusters and nanoparticles; electrochemistry; scanning probe microscopy; self-assembly; single molecule imaging; soft matter; surface and interfacial chemistry

Representative publication: Unsupervised vector-based classification of single-molecule charge transport data

Mario Lemmer, Michael S. Inkpen, Katja Kornysheva, Nicholas J. Long & Tim Albrecht
Nature Communications 7 (2016)  Article number: 12922 

 

In this paper, we outline a new approach to analysing single-molecule charge transport and other data, namely by Multi-Parameter Vector Classification (MPVC). This allows for largely unsupervised classification of large datasets, essentially without making any a priori assumptions of what they look like.

Areas of interest

Analytical chemistry; electrochemistry; magnetic resonance spectroscopy and imaging; simulation and modelling; soft matter

Representative publication: Quantitative, in-situ visualisation of metal ion dissolution and transport using 1H magnetic resonance imaging

Joshua M. Bray, Alison J. Davenport, Karl S. Ryder, and Melanie M. Britton
Angew. Chem. Int. Ed. 55 (2016) 9394 –9397

Britton_paper

This paper reports, for the first time, the quantitative mapping of metal ion dissolution and transport - non-invasively, in-situ, in 3D and in real-time - using 1H MRI of the electrolyte, overcoming a widely held belief that it is not possible to use MRI to visualise electrochemical processes near bulk-metals.  The dissolution of metallic copper is investigated, which is of significant industrial, societal and academic relevance. However, the insight gained from these measurements goes beyond the field of corrosion, and is of particular significance for the development of batteries. Currently, there are very few examples of MRI being used to quantitatively map the transport of electroactive species during battery operation and the few published have employed 7Li MRI and, thus, been restricted to studying lithium-ion batteries.  Yet, there are many other emerging metal-ion or metal-air batteries, involving electroactive species that cannot be visualised directly by MRI.  Crucially, the methodology reported in this paper can be readily modified and extended to provide valuable insights into these promising batteries technologies, as well as other electrochemical technologies.

Areas of interest

Clusters and nanoparticles; computational and theoretical chemistry; self-assembly; simulation and modelling; soft matter

Representative publication: Hierarchical self-assembly of colloidal magnetic particles into reconfigurable spherical structures

D. Morphew and D. Chakrabarti
Nanoscale 7 (2015) 8343-8350

Chakrabarti_paper

This computational study presents a novel approach to self-assemble viral capsid-like shells, exploiting a hierarchical self-assembly scheme for rationally designed colloidal building blocks, which closely resemble recently synthesized colloidal magnetic particles. The ability to reconfigure these shells makes the work especially significant as this feature is of particular importance for practical applications.

Areas of interest

Biophysical chemistry; catalysis; charge transfer and transport; clusters and nanoparticles; electrochemistry; environmental chemistry; self-assembly; surface and interfacial chemistry; synchrotron-based characterisation

Areas of interest

Fluorescence; biophysical chemistry and single molecule imaging

Representative publication: Combing of Genomic DNA from Droplets Containing Picograms of Material

Jochem Deen, Wouter Sempels, Raf De Dier, Jan Vermant, Peter Dedecker, Johan Hofkens, and Robert K. Neely
ACS Nano, 9 (2015) 809–816

Neely_paper

The paper describes a method for stretching DNA molecules onto a surface for imaging. We show that tiny amounts of DNA, from just a handful of human cells, can be captured efficiently. The paper looks at the mechanisms- the flow in the droplet and the surface chemistry- that  underpin this surprisingly efficient capture of genomic material and outlines how we might use it in the future to study the genetic material of organisms.

Areas of interest

Atmospheric chemistry; analytical chemistry; bio-nanotechnology; catalysis; clusters and nanoparticles; electrochemistry; self-assembly; surface and interfacial chemistry

Representative publication: The promoting effect of adsorbed carbon monoxide on the oxidation of alcohols on a gold catalyst

Paramaconi Rodriguez, Youngkook Kwon and Marc T. M. Koper
Nature Chemistry, 4 (2012) 177-182

Illuustration showing promoting effect of adsorbed carbon monoxide on the oxidation of alcohols on a gold catalyst

This paper an explanation for the unexpected and, until then, not-well understood electrocatalytic properties of gold surfaces.  While carbon monoxide typically acts as a poison, or poisoning intermediate, in the oxidation of alcohols in other metal surfaces i.e. Pt , this manuscript shows that  carbon monoxide can act as a promoter for the electrocatalytic oxidation of certain alcohols in alkaline media.

Areas of interest

Analytical science; bio-nanotechnology; optical sensors; simulation and modelling; soft matter.

Representative publication:A Proof-of-Principle Study for Performing Enzyme Bioassays Using Substrates Immobilized in a Leaky Optical Waveguide

R. Gupta, N.J. Goddard,
Sensors and Actuators B, 2017, 244, 549. DOI: 10.1016/j.snb.2017.01.05.

waveguide-biosensor-measuring-enzyme-activityThis work develops an original scheme for performing enzymatic bioassays in the volume (rather than on the surface) of an optical cavity. Enzyme substrate was covalently anchored to the optical cavity preventing loss of product from the sensing volume. The approach resulted in ~58 and 100 times more sensitive measurements than using total internal reflection and single pass absorption in microfluidic flow cells.

Associated research

Research associated with this unit also includes that undertaken by colleagues in other Schools, including Peter Winn, Chris Mayhew, Ulrich Günther.

Contact

Enquiries about specific aspects of their research areas should be addressed to individual research group leaders. For more general enquiries about working with the SBS Unit, please contact Professor Roy Johnson (IIS Unit Lead). Information on various postgraduate (PhD and Masters) degree opportunities can be found on our postraduate opportunities page.