Our students have been involved in new and exciting interdisciplinary research and have published in leading high impact journals including Nature Chemistry, Nature Communications, JACS, Angewandte Chemie, Applied Physics Letters, ACS Nano, Nano Letters, Advanced Materials, Nature Protocols, PloS one, and many others.
A full list of the work published by our NanoDTC Students, Associates and others, acknowledging the NanoDTC grants EP/G037221, EP/L015978 and EP/S022953/1 is below. If you want to view the papers on google scholar, see here.
Some papers published by our students are also featured below with some additional contextual information.
Last updated: Mar 2021
Looking inside lithium-ion batteries
Spectroscopy and Electrocatalysis for a Sustainable Future
From waste to fuel: quantifying sustainability
Novel spin states discovered in silicon-based artificial atoms
A step forward in efficient artificial photosynthesis
Self-assembling hydrogels on microfluidic droplets that respond to light or chemical stimuli by disassembling
2016
192.
Anna Lombardi Angela Demetriadou, Jan Mertens; Aizpurua, Javier
Anomalous spectral shifts in plasmonic nano-cavities Journal Article
In: META’16, The 7th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2016.
@article{demetriadouanomalous,
title = {Anomalous spectral shifts in plasmonic nano-cavities},
author = {Angela Demetriadou, Anna Lombardi, Jan Mertens, Ortwin Hess, Jeremy J Baumberg and Javier Aizpurua},
url = {https://spiral.imperial.ac.uk/handle/10044/1/39276},
year = {2016},
date = {2016-07-28},
journal = {META’16, The 7th International Conference on Metamaterials, Photonic Crystals and Plasmonics},
abstract = {Nanoplasmonics have the ability to confine light in extremely small nano-cavities. We show using a theoretical model, numerical calculations and measurements that for these tightly-coupled nanoplasmonic structures, the correlation between the field enhancement (near- field) resonance and the radiative (far-field) resonance breaks down. This dissociation is determined by the nanocavity’s geometry. The anomalous behaviour of plasmonic nanocavities is of significant importance for active and quantum plasmonics, where extreme nano-cavities are essential to observe strong coupling.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nanoplasmonics have the ability to confine light in extremely small nano-cavities. We show using a theoretical model, numerical calculations and measurements that for these tightly-coupled nanoplasmonic structures, the correlation between the field enhancement (near- field) resonance and the radiative (far-field) resonance breaks down. This dissociation is determined by the nanocavity’s geometry. The anomalous behaviour of plasmonic nanocavities is of significant importance for active and quantum plasmonics, where extreme nano-cavities are essential to observe strong coupling.
191.
Offeddu, Giovanni; Mayo, Romina Plitman; Oyen, Michelle L
Scale-dependent fluid permeability of tissue engineering scaffolds as a result of structure geometry and mechanics Journal Article
In: 2016.
@article{offedduscale,
title = {Scale-dependent fluid permeability of tissue engineering scaffolds as a result of structure geometry and mechanics},
author = {Giovanni Offeddu and Romina Plitman Mayo and Michelle L Oyen},
url = {https://www.frontiersin.org/10.3389/conf.FBIOE.2016.01.00111/event_abstract},
year = {2016},
date = {2016-03-30},
abstract = {Materials intended as tissue engineering scaffolds must be porous to accommodate cells and allow fluid flow for the transport of nutrients and removal of waste products. These are both necessary for long term cell viability[1]. The permeability of materials to fluid flow affects not only the biophysical stimuli received by cells seeded in the scaffold: the pressure and stress exerted by the fluid on such cells and the scaffold’s structure also depend on the permeability.
Hydrogels and freeze-dried constructs are commonly investigated as cell scaffolds, as one can control their porosity and consequent water content to achieve suitable conditions for cell seeding. However, the permeability of such materials is poorly understood as a result of their multi-scale structure: available models are too simplistic to describe the interaction between the fluid and the material making up the nano- or microporous architecture. The present work attempts to find generalized relationships to model the fluid permeability as a result of the multi-scale geometry of the structures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Materials intended as tissue engineering scaffolds must be porous to accommodate cells and allow fluid flow for the transport of nutrients and removal of waste products. These are both necessary for long term cell viability[1]. The permeability of materials to fluid flow affects not only the biophysical stimuli received by cells seeded in the scaffold: the pressure and stress exerted by the fluid on such cells and the scaffold’s structure also depend on the permeability.
Hydrogels and freeze-dried constructs are commonly investigated as cell scaffolds, as one can control their porosity and consequent water content to achieve suitable conditions for cell seeding. However, the permeability of such materials is poorly understood as a result of their multi-scale structure: available models are too simplistic to describe the interaction between the fluid and the material making up the nano- or microporous architecture. The present work attempts to find generalized relationships to model the fluid permeability as a result of the multi-scale geometry of the structures.
Hydrogels and freeze-dried constructs are commonly investigated as cell scaffolds, as one can control their porosity and consequent water content to achieve suitable conditions for cell seeding. However, the permeability of such materials is poorly understood as a result of their multi-scale structure: available models are too simplistic to describe the interaction between the fluid and the material making up the nano- or microporous architecture. The present work attempts to find generalized relationships to model the fluid permeability as a result of the multi-scale geometry of the structures.
190.
Beeson, Harry James
Templated Electrodeposition for Nanostructured Photovoltaic Applications Journal Article
In: 2016.
@article{beeson2016templated,
title = {Templated Electrodeposition for Nanostructured Photovoltaic Applications},
author = {Harry James Beeson},
url = {https://cdn.unifr.ch/ami-db/uploads/file/a16ce05d-85cd-4ba3-b7ac-8cf1e625a36f/Thesis_HarryBeeson.pdf},
year = {2016},
date = {2016-01-01},
abstract = {This thesis explores the use of templated electrodeposition for the fabrication of nanostructured ‘next-generation’ solar cells. The main project investigates the electropolymerisation of polythiophene around gyroid-structured templates to give organic, bulk heterojunction solar cells with a well-defined, regular donor:acceptor nanostructure. There are three broad motivations for this project: investigating the suitability of templated electropolymerisation for fabricating optoelectronic devices with precisely-controlled nanostructure; preparing organic solar cells with well-defined structure to aid further investigation of their operation; and assessing the suitability of the gyroid bulk heterojunction structure for highperformance solar cells. Additional, briefer projects investigate electrodeposition for the fabrication of perovskite-based solar cells.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This thesis explores the use of templated electrodeposition for the fabrication of nanostructured ‘next-generation’ solar cells. The main project investigates the electropolymerisation of polythiophene around gyroid-structured templates to give organic, bulk heterojunction solar cells with a well-defined, regular donor:acceptor nanostructure. There are three broad motivations for this project: investigating the suitability of templated electropolymerisation for fabricating optoelectronic devices with precisely-controlled nanostructure; preparing organic solar cells with well-defined structure to aid further investigation of their operation; and assessing the suitability of the gyroid bulk heterojunction structure for highperformance solar cells. Additional, briefer projects investigate electrodeposition for the fabrication of perovskite-based solar cells.
189.
Sitenko, Yurii A
Hot dense magnetized ultrarelativistic spinor matter in a slab Journal Article
In: Physical Review D, vol. 94, no. 8, pp. 085014, 2016.
@article{sitenko2016hot,
title = {Hot dense magnetized ultrarelativistic spinor matter in a slab},
author = {Yurii A Sitenko},
url = {https://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.085014},
year = {2016},
date = {2016-01-01},
journal = {Physical Review D},
volume = {94},
number = {8},
pages = {085014},
publisher = {American Physical Society},
abstract = {Properties of hot dense ultrarelativistic spinor matter in a slab of finite width, placed in a transverse uniform magnetic field, are studied. The admissible set of boundary conditions is determined by the requirement that spinor matter be confined inside the slab. In thermal equilibrium, the chiral separation effect in the slab is shown to depend on both temperature and chemical potential; this is distinct from the unrealistic case of the magnetic field filling the unbounded (infinite) medium, when the effect is temperature independent. In the realistic case of the slab, a stepwise behavior of the axial current density at zero temperature is smoothed out as temperature increases, turning into a linear behavior at infinitely large temperature. A choice of boundary conditions can facilitate either augmentation or attenuation of the chiral separation effect; in particular, the effect can persist even at zero chemical potential, if temperature is finite. Thus the boundary condition can serve as a source that is additional to the spinor matter density.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Properties of hot dense ultrarelativistic spinor matter in a slab of finite width, placed in a transverse uniform magnetic field, are studied. The admissible set of boundary conditions is determined by the requirement that spinor matter be confined inside the slab. In thermal equilibrium, the chiral separation effect in the slab is shown to depend on both temperature and chemical potential; this is distinct from the unrealistic case of the magnetic field filling the unbounded (infinite) medium, when the effect is temperature independent. In the realistic case of the slab, a stepwise behavior of the axial current density at zero temperature is smoothed out as temperature increases, turning into a linear behavior at infinitely large temperature. A choice of boundary conditions can facilitate either augmentation or attenuation of the chiral separation effect; in particular, the effect can persist even at zero chemical potential, if temperature is finite. Thus the boundary condition can serve as a source that is additional to the spinor matter density.
188.
Bell, Nicholas AW; Muthukumar, Murugappan; Keyser, Ulrich F
Translocation frequency of double-stranded DNA through a solid-state nanopore Journal Article
In: Physical Review E, vol. 93, no. 2, pp. 022401, 2016.
@article{bell2016translocation,
title = {Translocation frequency of double-stranded DNA through a solid-state nanopore},
author = {Nicholas AW Bell and Murugappan Muthukumar and Ulrich F Keyser},
url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.93.022401},
year = {2016},
date = {2016-01-01},
journal = {Physical Review E},
volume = {93},
number = {2},
pages = {022401},
publisher = {American Physical Society},
abstract = {Solid-state nanopores are single-molecule sensors that measure changes in ionic current as charged polymers such as DNA pass through. Here, we present comprehensive experiments on the length, voltage, and salt dependence of the frequency of double-stranded DNA translocations through conical quartz nanopores with mean opening diameter 15 nm. We observe an entropic barrier-limited, length-dependent translocation frequency at 4M LiCl salt concentration and a drift-dominated, length-independent translocation frequency at 1M KCl salt concentration. These observations are described by a unifying convection-diffusion equation, which includes the contribution of an entropic barrier for polymer entry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Solid-state nanopores are single-molecule sensors that measure changes in ionic current as charged polymers such as DNA pass through. Here, we present comprehensive experiments on the length, voltage, and salt dependence of the frequency of double-stranded DNA translocations through conical quartz nanopores with mean opening diameter 15 nm. We observe an entropic barrier-limited, length-dependent translocation frequency at 4M LiCl salt concentration and a drift-dominated, length-independent translocation frequency at 1M KCl salt concentration. These observations are described by a unifying convection-diffusion equation, which includes the contribution of an entropic barrier for polymer entry.
187.
Lombardi, Anna; Demetriadou, Angela; Weller, Lee; Andrae, Patrick; Benz, Felix; Chikkaraddy, Rohit; Aizpurua, Javier; Baumberg, Jeremy J
Anomalous spectral shift of near-and far-field plasmonic resonances in nanogaps Journal Article
In: ACS photonics, vol. 3, no. 3, pp. 471–477, 2016.
@article{lombardi2016anomalous,
title = {Anomalous spectral shift of near-and far-field plasmonic resonances in nanogaps},
author = {Anna Lombardi and Angela Demetriadou and Lee Weller and Patrick Andrae and Felix Benz and Rohit Chikkaraddy and Javier Aizpurua and Jeremy J Baumberg},
url = {https://pubs.acs.org/doi/abs/10.1021/acsphotonics.5b00707},
year = {2016},
date = {2016-01-01},
journal = {ACS photonics},
volume = {3},
number = {3},
pages = {471--477},
publisher = {American Chemical Society},
abstract = {The near-field and far-field spectral response of plasmonic systems are often assumed to be identical, due to the lack of methods that can directly compare and correlate both responses under similar environmental conditions. We develop a widely tunable optical technique to probe the near-field resonances within individual plasmonic nanostructures that can be directly compared to the corresponding far-field response. In tightly coupled nanoparticle-on-mirror constructs with nanometer-sized gaps we find >40 meV blue-shifts of the near-field compared to the dark-field scattering peak, which agrees with full electromagnetic simulations. Using a transformation optics approach, we show such shifts arise from the different spectral interference between different gap modes in the near- and far-field. The control and tuning of near-field and far-field responses demonstrated here is of paramount importance in the design of optical nanostructures for field-enhanced spectroscopy, as well as to control near-field activity monitored through the far-field of nano-optical devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The near-field and far-field spectral response of plasmonic systems are often assumed to be identical, due to the lack of methods that can directly compare and correlate both responses under similar environmental conditions. We develop a widely tunable optical technique to probe the near-field resonances within individual plasmonic nanostructures that can be directly compared to the corresponding far-field response. In tightly coupled nanoparticle-on-mirror constructs with nanometer-sized gaps we find >40 meV blue-shifts of the near-field compared to the dark-field scattering peak, which agrees with full electromagnetic simulations. Using a transformation optics approach, we show such shifts arise from the different spectral interference between different gap modes in the near- and far-field. The control and tuning of near-field and far-field responses demonstrated here is of paramount importance in the design of optical nanostructures for field-enhanced spectroscopy, as well as to control near-field activity monitored through the far-field of nano-optical devices.
186.
Michan, Alison L; Leskes, Michal; Grey, Clare P
Voltage dependent solid electrolyte interphase formation in silicon electrodes: monitoring the formation of organic decomposition products Journal Article
In: Chemistry of Materials, vol. 28, no. 1, pp. 385–398, 2016.
@article{michan2016voltage,
title = {Voltage dependent solid electrolyte interphase formation in silicon electrodes: monitoring the formation of organic decomposition products},
author = {Alison L Michan and Michal Leskes and Clare P Grey},
url = {https://pubs.acs.org/doi/abs/10.1021/acs.chemmater.5b04408},
year = {2016},
date = {2016-01-01},
journal = {Chemistry of Materials},
volume = {28},
number = {1},
pages = {385--398},
publisher = {American Chemical Society},
abstract = {The solid electrolyte interphase (SEI) passivating layer that grows on all battery electrodes during cycling is critical to the long-term capacity retention of lithium-ion batteries. Yet, it is inherently difficult to study because of its nanoscale thickness, amorphous composite structure, and air sensitivity. Here, we employ an experimental strategy using 1H, 7Li, 19F, and 13C solid-state nuclear magnetic resonance (ssNMR) to gain insight into the decomposition products in the SEI formed on silicon electrodes, the uncontrolled growth of the SEI representing a major failure mechanism that prevents the practical use of silicon in lithium-ion batteries. The voltage dependent formation of the SEI is confirmed, with the SEI growth correlating with irreversible capacity. By studying both conductive carbon and mixed Si/C composite electrodes separately, a correlation with increased capacity loss of the composite system and the low-voltage silicon plateau is demonstrated. Using selective 13C labeling, we detect decomposition products of the electrolyte solvents ethylene carbonate (EC) and dimethyl carbonate (DMC) independently. EC decomposition products are present in higher concentrations and are dominated by oligomer species. Lithium semicarbonates, lithium fluoride, and lithium carbonate products are also seen. Ab initio calculations have been carried out to aid in the assignment of NMR shifts. ssNMR applied to both rinsed and unrinsed electrodes show that the organics are easily rinsed away, suggesting that they are located on the outer layer of the SEI.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The solid electrolyte interphase (SEI) passivating layer that grows on all battery electrodes during cycling is critical to the long-term capacity retention of lithium-ion batteries. Yet, it is inherently difficult to study because of its nanoscale thickness, amorphous composite structure, and air sensitivity. Here, we employ an experimental strategy using 1H, 7Li, 19F, and 13C solid-state nuclear magnetic resonance (ssNMR) to gain insight into the decomposition products in the SEI formed on silicon electrodes, the uncontrolled growth of the SEI representing a major failure mechanism that prevents the practical use of silicon in lithium-ion batteries. The voltage dependent formation of the SEI is confirmed, with the SEI growth correlating with irreversible capacity. By studying both conductive carbon and mixed Si/C composite electrodes separately, a correlation with increased capacity loss of the composite system and the low-voltage silicon plateau is demonstrated. Using selective 13C labeling, we detect decomposition products of the electrolyte solvents ethylene carbonate (EC) and dimethyl carbonate (DMC) independently. EC decomposition products are present in higher concentrations and are dominated by oligomer species. Lithium semicarbonates, lithium fluoride, and lithium carbonate products are also seen. Ab initio calculations have been carried out to aid in the assignment of NMR shifts. ssNMR applied to both rinsed and unrinsed electrodes show that the organics are easily rinsed away, suggesting that they are located on the outer layer of the SEI.
185.
Jellicoe, Tom C; Richter, Johannes M; Glass, Hugh FJ; Tabachnyk, Maxim; Brady, Ryan; Dutton, Siân E; Rao, Akshay; Friend, Richard H; Credgington, Dan; Greenham, Neil C; others,
Synthesis and optical properties of lead-free cesium tin halide perovskite nanocrystals Journal Article
In: Journal of the American Chemical Society, vol. 138, no. 9, pp. 2941–2944, 2016.
@article{jellicoe2016synthesis,
title = {Synthesis and optical properties of lead-free cesium tin halide perovskite nanocrystals},
author = {Tom C Jellicoe and Johannes M Richter and Hugh FJ Glass and Maxim Tabachnyk and Ryan Brady and Siân E Dutton and Akshay Rao and Richard H Friend and Dan Credgington and Neil C Greenham and others},
url = {https://pubs.acs.org/doi/abs/10.1021/jacs.5b13470},
year = {2016},
date = {2016-01-01},
journal = {Journal of the American Chemical Society},
volume = {138},
number = {9},
pages = {2941--2944},
publisher = {American Chemical Society},
abstract = {Metal halide perovskite crystal structures have emerged as a class of optoelectronic materials, which combine the ease of solution processability with excellent optical absorption and emission qualities. Restricting the physical dimensions of the perovskite crystallites to a few nanometers can also unlock spatial confinement effects, which allow large spectral tunability and high luminescence quantum yields at low excitation densities. However, the most promising perovskite structures rely on lead as a cationic species, thereby hindering commercial application. The replacement of lead with nontoxic alternatives such as tin has been demonstrated in bulk films, but not in spatially confined nanocrystals. Here, we synthesize CsSnX3 (X = Cl, Cl0.5Br0.5, Br, Br0.5I0.5, I) perovskite nanocrystals and provide evidence of their spectral tunability through both quantum confinement effects and control of the anionic composition. We show that luminescence from Sn-based perovskite nanocrystals occurs on pico- to nanosecond time scales via two spectrally distinct radiative decay processes, which we assign to band-to-band emission and radiative recombination at shallow intrinsic defect sites.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Metal halide perovskite crystal structures have emerged as a class of optoelectronic materials, which combine the ease of solution processability with excellent optical absorption and emission qualities. Restricting the physical dimensions of the perovskite crystallites to a few nanometers can also unlock spatial confinement effects, which allow large spectral tunability and high luminescence quantum yields at low excitation densities. However, the most promising perovskite structures rely on lead as a cationic species, thereby hindering commercial application. The replacement of lead with nontoxic alternatives such as tin has been demonstrated in bulk films, but not in spatially confined nanocrystals. Here, we synthesize CsSnX3 (X = Cl, Cl0.5Br0.5, Br, Br0.5I0.5, I) perovskite nanocrystals and provide evidence of their spectral tunability through both quantum confinement effects and control of the anionic composition. We show that luminescence from Sn-based perovskite nanocrystals occurs on pico- to nanosecond time scales via two spectrally distinct radiative decay processes, which we assign to band-to-band emission and radiative recombination at shallow intrinsic defect sites.
184.
Salmon, Andrew R; Esteban, Ruben; Taylor, Richard W; Hugall, James T; Smith, Clive A; Whyte, Graeme; Scherman, Oren A; Aizpurua, Javier; Abell, Chris; Baumberg, Jeremy J
Monitoring Early-Stage Nanoparticle Assembly in Microdroplets by Optical Spectroscopy and SERS Journal Article
In: Small, vol. 12, no. 13, pp. 1788–1796, 2016.
@article{salmon2016monitoring,
title = {Monitoring Early-Stage Nanoparticle Assembly in Microdroplets by Optical Spectroscopy and SERS},
author = {Andrew R Salmon and Ruben Esteban and Richard W Taylor and James T Hugall and Clive A Smith and Graeme Whyte and Oren A Scherman and Javier Aizpurua and Chris Abell and Jeremy J Baumberg},
url = {https://onlinelibrary.wiley.com/doi/full/10.1002/smll.201503513},
year = {2016},
date = {2016-01-01},
journal = {Small},
volume = {12},
number = {13},
pages = {1788--1796},
abstract = {Microfluidic microdroplets have increasingly found application in biomolecular sensing as well as nanomaterials growth. More recently the synthesis of plasmonic nanostructures in microdroplets has led to surface‐enhanced Raman spectroscopy (SERS)‐based sensing applications. However, the study of nanoassembly in microdroplets has previously been hindered by the lack of on‐chip characterization tools, particularly at early timescales. Enabled by a refractive index matching microdroplet formulation, dark‐field spectroscopy is exploited to directly track the formation of nanometer‐spaced gold nanoparticle assemblies in microdroplets. Measurements in flow provide millisecond time resolution through the assembly process, allowing identification of a regime where dimer formation dominates the dark‐field scattering and SERS. Furthurmore, it is shown that small numbers of nanoparticles can be isolated in microdroplets, paving the way for simple high‐yield assembly, isolation, and sorting of few nanoparticle structures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Microfluidic microdroplets have increasingly found application in biomolecular sensing as well as nanomaterials growth. More recently the synthesis of plasmonic nanostructures in microdroplets has led to surface‐enhanced Raman spectroscopy (SERS)‐based sensing applications. However, the study of nanoassembly in microdroplets has previously been hindered by the lack of on‐chip characterization tools, particularly at early timescales. Enabled by a refractive index matching microdroplet formulation, dark‐field spectroscopy is exploited to directly track the formation of nanometer‐spaced gold nanoparticle assemblies in microdroplets. Measurements in flow provide millisecond time resolution through the assembly process, allowing identification of a regime where dimer formation dominates the dark‐field scattering and SERS. Furthurmore, it is shown that small numbers of nanoparticles can be isolated in microdroplets, paving the way for simple high‐yield assembly, isolation, and sorting of few nanoparticle structures.
183.
Bell, Nicholas AW; Keyser, Ulrich F
Research data supporting "Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores" Journal Article
In: 2016.
@article{bell2016research,
title = {Research data supporting "Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores"},
author = {Nicholas AW Bell and Ulrich F Keyser},
url = {https://www.repository.cam.ac.uk/handle/1810/253976},
year = {2016},
date = {2016-01-01},
publisher = {University of Cambridge},
abstract = {The data set contains ionic current traces and barcode assignment calls for each Figure in the main text of the paper. Further details are given in notes files for each Figure data set.
This research data supports “Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores” which has been published in “Nature Nanotechnology”.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The data set contains ionic current traces and barcode assignment calls for each Figure in the main text of the paper. Further details are given in notes files for each Figure data set.
This research data supports “Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores” which has been published in “Nature Nanotechnology”.
This research data supports “Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores” which has been published in “Nature Nanotechnology”.
182.
Bell, Nicholas AW; Kong, Jinglin; Keyser, Ulrich F
DNA Nanostructures for Single Molecule Protein Sensing with Nanopores Journal Article
In: Biophysical Journal, vol. 110, no. 3, pp. 654a, 2016.
@article{bell2016dna,
title = {DNA Nanostructures for Single Molecule Protein Sensing with Nanopores},
author = {Nicholas AW Bell and Jinglin Kong and Ulrich F Keyser},
url = {https://www.cell.com/biophysj/fulltext/S0006-3495(15)04683-4},
year = {2016},
date = {2016-01-01},
journal = {Biophysical Journal},
volume = {110},
number = {3},
pages = {654a},
publisher = {Elsevier},
abstract = {Solid-state nanopore sensing of proteins presents challenges due to the fast timescale of translocation and the difficulty in discriminating signals from different proteins. In this work we describe a new method for nanopore protein sensing which allows us to address these issues by introducing chemical selectivity into solid-state nanopore measurements. We designed linear DNA nanostructures by hybridising nearly two hundred oligonucleotides to the m13mp18 virus genome. This engineered DNA nanostructure allows positioning of protein binding sites at nanometre accurate intervals along its contour via DNA conjugation chemistry. The ionic current signal of each translocating DNA nanostructure shows an extra characteristic modulation after incubation with a target protein due its binding at the desired position. We also show how multiple protein species can be simultaneously detected at nanomolar concentration levels using this technique.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Solid-state nanopore sensing of proteins presents challenges due to the fast timescale of translocation and the difficulty in discriminating signals from different proteins. In this work we describe a new method for nanopore protein sensing which allows us to address these issues by introducing chemical selectivity into solid-state nanopore measurements. We designed linear DNA nanostructures by hybridising nearly two hundred oligonucleotides to the m13mp18 virus genome. This engineered DNA nanostructure allows positioning of protein binding sites at nanometre accurate intervals along its contour via DNA conjugation chemistry. The ionic current signal of each translocating DNA nanostructure shows an extra characteristic modulation after incubation with a target protein due its binding at the desired position. We also show how multiple protein species can be simultaneously detected at nanomolar concentration levels using this technique.
181.
Kong, Jinglin; Bell, Nicholas; Keyser, Ulrich
Quantifying Protein Concentration using Designed DNA Carriers and Solid-State Nanopores Journal Article
In: Biophysical Journal, vol. 110, no. 3, pp. 334a, 2016.
@article{kong2016quantifying,
title = {Quantifying Protein Concentration using Designed DNA Carriers and Solid-State Nanopores},
author = {Jinglin Kong and Nicholas Bell and Ulrich Keyser},
url = {https://www.cell.com/biophysj/fulltext/S0006-3495(15)02979-3},
year = {2016},
date = {2016-01-01},
journal = {Biophysical Journal},
volume = {110},
number = {3},
pages = {334a},
publisher = {Elsevier},
abstract = {Designed “DNA carriers” have been proposed as a new method for nanopore based specific protein detection. Target proteins bind to the DNA carrier at defined positions creating a second level transient current drop against the background DNA translocation. In this work, we investigate the ability of this method to quantify protein concentrations. After incubation with target proteins of different concentrations, the fraction of DNA translocations showing a secondary current spike allows for quantification of the corresponding protein concentration. The protein concentration dependence is measured with two standard systems: biotin-streptavidin and digoxigenin-antibody system, at nanomolar or sub-nanomolar protein concentrations. The results demonstrate a dynamic range of ∼0.1 to 0.9 occupied fraction and show the potential for quantitative and specific protein detection using the DNA carrier method.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Designed “DNA carriers” have been proposed as a new method for nanopore based specific protein detection. Target proteins bind to the DNA carrier at defined positions creating a second level transient current drop against the background DNA translocation. In this work, we investigate the ability of this method to quantify protein concentrations. After incubation with target proteins of different concentrations, the fraction of DNA translocations showing a secondary current spike allows for quantification of the corresponding protein concentration. The protein concentration dependence is measured with two standard systems: biotin-streptavidin and digoxigenin-antibody system, at nanomolar or sub-nanomolar protein concentrations. The results demonstrate a dynamic range of ∼0.1 to 0.9 occupied fraction and show the potential for quantitative and specific protein detection using the DNA carrier method.
180.
Tesoro, Salvatore; Göpfrich, K; Kartanas, Tadas; Keyser, Ulrich Felix; Ahnert, Sebastian Edmund
Nondeterministic self-assembly with asymmetric interactions Journal Article
In: Physical Review E, vol. 94, no. 2, pp. 022404, 2016.
@article{tesoro2016nondeterministic,
title = {Nondeterministic self-assembly with asymmetric interactions},
author = {Salvatore Tesoro and K Göpfrich and Tadas Kartanas and Ulrich Felix Keyser and Sebastian Edmund Ahnert},
url = {https://journals.aps.org/pre/abstract/10.1103/PhysRevE.94.022404},
year = {2016},
date = {2016-01-01},
journal = {Physical Review E},
volume = {94},
number = {2},
pages = {022404},
publisher = {American Physical Society},
abstract = {We investigate general properties of nondeterministic self-assembly with asymmetric interactions, using a computational model and DNA tile assembly experiments. By contrasting symmetric and asymmetric interactions we show that the latter can lead to self-limiting cluster growth. Furthermore, by adjusting the relative abundance of self-assembly particles in a two-particle mixture, we are able to tune the final sizes of these clusters. We show that this is a fundamental property of asymmetric interactions, which has potential applications in bioengineering, and provides insights into the study of diseases caused by protein aggregation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate general properties of nondeterministic self-assembly with asymmetric interactions, using a computational model and DNA tile assembly experiments. By contrasting symmetric and asymmetric interactions we show that the latter can lead to self-limiting cluster growth. Furthermore, by adjusting the relative abundance of self-assembly particles in a two-particle mixture, we are able to tune the final sizes of these clusters. We show that this is a fundamental property of asymmetric interactions, which has potential applications in bioengineering, and provides insights into the study of diseases caused by protein aggregation.
179.
Griffin, John M; Forse, Alexander C; Grey, Clare P
Solid-state NMR studies of supercapacitors Journal Article
In: Solid state nuclear magnetic resonance, vol. 74, pp. 16–35, 2016.
@article{griffin2016solid,
title = {Solid-state NMR studies of supercapacitors},
author = {John M Griffin and Alexander C Forse and Clare P Grey},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0926204016300042},
year = {2016},
date = {2016-01-01},
journal = {Solid state nuclear magnetic resonance},
volume = {74},
pages = {16--35},
publisher = {Academic Press},
abstract = {Electrochemical double-layer capacitors, or ‘supercapacitors’ are attracting increasing attention as high-power energy storage devices for a wide range of technological applications. These devices store charge through electrostatic interactions between liquid electrolyte ions and the surfaces of porous carbon electrodes. However, many aspects of the fundamental mechanism of supercapacitance are still not well understood, and there is a lack of experimental techniques which are capable of studying working devices. Recently, solid-state NMR has emerged as a powerful tool for studying the local environments and behaviour of electrolyte ions in supercapacitor electrodes. In this Trends article, we review these recent developments and applications. We first discuss the basic principles underlying the mechanism of supercapacitance, as well as the key NMR observables that are relevant to the study of supercapacitor electrodes. We then review some practical aspects of the study of working devices using ex situ and in situ methodologies and explain the key advances that these techniques have allowed on the study of supercapacitor charging mechanisms. NMR experiments have revealed that the pores of the carbon electrodes contain a significant number of electrolyte ions in the absence of any charging potential. This has important implications for the molecular mechanisms of supercapacitance, as charge can be stored by different ion adsorption/desorption processes. Crucially, we show how in situ NMR experiments can be used to quantitatively study and characterise the charging mechanism, with the experiments providing the most detailed picture of charge storage to date, offering the opportunity to design enhanced devices. Finally, an outlook for future directions for solid-state NMR in supercapacitor research is offered.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Electrochemical double-layer capacitors, or ‘supercapacitors’ are attracting increasing attention as high-power energy storage devices for a wide range of technological applications. These devices store charge through electrostatic interactions between liquid electrolyte ions and the surfaces of porous carbon electrodes. However, many aspects of the fundamental mechanism of supercapacitance are still not well understood, and there is a lack of experimental techniques which are capable of studying working devices. Recently, solid-state NMR has emerged as a powerful tool for studying the local environments and behaviour of electrolyte ions in supercapacitor electrodes. In this Trends article, we review these recent developments and applications. We first discuss the basic principles underlying the mechanism of supercapacitance, as well as the key NMR observables that are relevant to the study of supercapacitor electrodes. We then review some practical aspects of the study of working devices using ex situ and in situ methodologies and explain the key advances that these techniques have allowed on the study of supercapacitor charging mechanisms. NMR experiments have revealed that the pores of the carbon electrodes contain a significant number of electrolyte ions in the absence of any charging potential. This has important implications for the molecular mechanisms of supercapacitance, as charge can be stored by different ion adsorption/desorption processes. Crucially, we show how in situ NMR experiments can be used to quantitatively study and characterise the charging mechanism, with the experiments providing the most detailed picture of charge storage to date, offering the opportunity to design enhanced devices. Finally, an outlook for future directions for solid-state NMR in supercapacitor research is offered.
178.
Pazos-Outón, Luis M; Szumilo, Monika; Lamboll, Robin; Richter, Johannes M; Crespo-Quesada, Micaela; Abdi-Jalebi, Mojtaba; Beeson, Harry J; Vru'cini'c, Milan; Alsari, Mejd; Snaith, Henry J; others,
Photon recycling in lead iodide perovskite solar cells Journal Article
In: Science, vol. 351, no. 6280, pp. 1430–1433, 2016.
@article{pazos2016photon,
title = {Photon recycling in lead iodide perovskite solar cells},
author = {Luis M Pazos-Outón and Monika Szumilo and Robin Lamboll and Johannes M Richter and Micaela Crespo-Quesada and Mojtaba Abdi-Jalebi and Harry J Beeson and Milan Vru{'c}ini{'c} and Mejd Alsari and Henry J Snaith and others},
url = {https://science.sciencemag.org/content/351/6280/1430.abstract},
year = {2016},
date = {2016-01-01},
journal = {Science},
volume = {351},
number = {6280},
pages = {1430--1433},
publisher = {American Association for the Advancement of Science},
abstract = {Lead-halide perovskites have emerged as high-performance photovoltaic materials. We mapped the propagation of photogenerated luminescence and charges from a local photoexcitation spot in thin films of lead tri-iodide perovskites. We observed light emission at distances of ≥50 micrometers and found that the peak of the internal photon spectrum red-shifts from 765 to ≥800 nanometers. We used a lateral-contact solar cell with selective electron- and hole-collecting contacts and observed that charge extraction for photoexcitation >50 micrometers away from the contacts arose from repeated recycling between photons and electron-hole pairs. Thus, energy transport is not limited by diffusive charge transport but can occur over long distances through multiple absorption-diffusion-emission events. This process creates high excitation densities within the perovskite layer and allows high open-circuit voltages.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lead-halide perovskites have emerged as high-performance photovoltaic materials. We mapped the propagation of photogenerated luminescence and charges from a local photoexcitation spot in thin films of lead tri-iodide perovskites. We observed light emission at distances of ≥50 micrometers and found that the peak of the internal photon spectrum red-shifts from 765 to ≥800 nanometers. We used a lateral-contact solar cell with selective electron- and hole-collecting contacts and observed that charge extraction for photoexcitation >50 micrometers away from the contacts arose from repeated recycling between photons and electron-hole pairs. Thus, energy transport is not limited by diffusive charge transport but can occur over long distances through multiple absorption-diffusion-emission events. This process creates high excitation densities within the perovskite layer and allows high open-circuit voltages.
177.
Bell, Nicholas AW; Keyser, Ulrich F
Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores Journal Article
In: Nature nanotechnology, vol. 11, no. 7, pp. 645, 2016.
@article{bell2016digitally,
title = {Digitally encoded DNA nanostructures for multiplexed, single-molecule protein sensing with nanopores},
author = {Nicholas AW Bell and Ulrich F Keyser},
url = {https://www.nature.com/articles/nnano.2016.50.pdf?origin=ppub},
year = {2016},
date = {2016-01-01},
journal = {Nature nanotechnology},
volume = {11},
number = {7},
pages = {645},
publisher = {Nature Publishing Group},
abstract = {The simultaneous detection of a large number of different analytes is important in bionanotechnology research and in
diagnostic applications. Nanopore sensing is an attractive method in this regard as the approach can be integrated into
small, portable device architectures, and there is significant potential for detecting multiple sub-populations in a sample.
Here, we show that highly multiplexed sensing of single molecules can be achieved with solid-state nanopores by using
digitally encoded DNA nanostructures. Based on the principles of DNA origami, we designed a library of DNA
nanostructures in which each member contains a unique barcode; each bit in the barcode is signalled by the presence or
absence of multiple DNA dumbbell hairpins. We show that a 3-bit barcode can be assigned with 94% accuracy by
electrophoretically driving the DNA structures through a solid-state nanopore. Select members of the library were then
functionalized to detect a single, specific antibody through antigen presentation at designed positions on the DNA. This
allows us to simultaneously detect four different antibodies of the same isotype at nanomolar concentration levels.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The simultaneous detection of a large number of different analytes is important in bionanotechnology research and in
diagnostic applications. Nanopore sensing is an attractive method in this regard as the approach can be integrated into
small, portable device architectures, and there is significant potential for detecting multiple sub-populations in a sample.
Here, we show that highly multiplexed sensing of single molecules can be achieved with solid-state nanopores by using
digitally encoded DNA nanostructures. Based on the principles of DNA origami, we designed a library of DNA
nanostructures in which each member contains a unique barcode; each bit in the barcode is signalled by the presence or
absence of multiple DNA dumbbell hairpins. We show that a 3-bit barcode can be assigned with 94% accuracy by
electrophoretically driving the DNA structures through a solid-state nanopore. Select members of the library were then
functionalized to detect a single, specific antibody through antigen presentation at designed positions on the DNA. This
allows us to simultaneously detect four different antibodies of the same isotype at nanomolar concentration levels.
diagnostic applications. Nanopore sensing is an attractive method in this regard as the approach can be integrated into
small, portable device architectures, and there is significant potential for detecting multiple sub-populations in a sample.
Here, we show that highly multiplexed sensing of single molecules can be achieved with solid-state nanopores by using
digitally encoded DNA nanostructures. Based on the principles of DNA origami, we designed a library of DNA
nanostructures in which each member contains a unique barcode; each bit in the barcode is signalled by the presence or
absence of multiple DNA dumbbell hairpins. We show that a 3-bit barcode can be assigned with 94% accuracy by
electrophoretically driving the DNA structures through a solid-state nanopore. Select members of the library were then
functionalized to detect a single, specific antibody through antigen presentation at designed positions on the DNA. This
allows us to simultaneously detect four different antibodies of the same isotype at nanomolar concentration levels.
176.
Kong, Jinglin; Bell, Nicholas AW; Keyser, Ulrich F
Quantifying nanomolar protein concentrations using designed DNA carriers and solid-state nanopores Journal Article
In: Nano letters, vol. 16, no. 6, pp. 3557–3562, 2016.
@article{kong2016quantifyingb,
title = {Quantifying nanomolar protein concentrations using designed DNA carriers and solid-state nanopores},
author = {Jinglin Kong and Nicholas AW Bell and Ulrich F Keyser},
url = {https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.6b00627},
year = {2016},
date = {2016-01-01},
journal = {Nano letters},
volume = {16},
number = {6},
pages = {3557--3562},
publisher = {American Chemical Society},
abstract = {Designed “DNA carriers” have been proposed as a new method for nanopore based specific protein detection. In this system, target protein molecules bind to a long DNA strand at a defined position creating a second level transient current drop against the background DNA translocation. Here, we demonstrate the ability of this system to quantify protein concentrations in the nanomolar range. After incubation with target protein at different concentrations, the fraction of DNA translocations showing a secondary current spike allows for the quantification of the corresponding protein concentration. For our proof-of-principle experiments we use two standard binding systems, biotin–streptavidin and digoxigenin–antidigoxigenin, that allow for measurements of the concentration down to the low nanomolar range. The results demonstrate the potential for a novel quantitative and specific protein detection scheme using the DNA carrier method.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Designed “DNA carriers” have been proposed as a new method for nanopore based specific protein detection. In this system, target protein molecules bind to a long DNA strand at a defined position creating a second level transient current drop against the background DNA translocation. Here, we demonstrate the ability of this system to quantify protein concentrations in the nanomolar range. After incubation with target protein at different concentrations, the fraction of DNA translocations showing a secondary current spike allows for the quantification of the corresponding protein concentration. For our proof-of-principle experiments we use two standard binding systems, biotin–streptavidin and digoxigenin–antidigoxigenin, that allow for measurements of the concentration down to the low nanomolar range. The results demonstrate the potential for a novel quantitative and specific protein detection scheme using the DNA carrier method.
175.
R Mansel Tarun Vemulkar, Amalio Fernandez-Pacheco; Cowburn, Richard P
In: 2016.
@article{vemulkar2016research,
title = {Research data supporting "Towards Flexible Spintronics: Perpendicularly Magnetized Synthetic Antiferromagnetic Thin films and Nanowires On Polyimide Substrates"},
author = {Tarun Vemulkar, R Mansel, Amalio Fernandez-Pacheco and Richard P Cowburn},
url = {https://aspace.repository.cam.ac.uk/handle/1810/253981},
year = {2016},
date = {2016-01-01},
publisher = {University of Cambridge},
abstract = {Magnetometry and relevant atomic force microscopy data corresponding to the figures in the publication.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Magnetometry and relevant atomic force microscopy data corresponding to the figures in the publication.
174.
Whiter, Richard A; Calahorra, Yonatan; Ou, Canlin; Kar-Narayan, Sohini
Observation of confinement-induced self-poling effects in ferroelectric polymer nanowires grown by template wetting Journal Article
In: Macromolecular Materials and Engineering, vol. 301, no. 9, pp. 1016–1025, 2016.
@article{whiter2016observation,
title = {Observation of confinement-induced self-poling effects in ferroelectric polymer nanowires grown by template wetting},
author = {Richard A Whiter and Yonatan Calahorra and Canlin Ou and Sohini Kar-Narayan},
url = {https://onlinelibrary.wiley.com/doi/full/10.1002/mame.201600135},
year = {2016},
date = {2016-01-01},
journal = {Macromolecular Materials and Engineering},
volume = {301},
number = {9},
pages = {1016--1025},
abstract = {Ferroelectric polymer nanowires grown using a template‐wetting method are shown to achieve an orientated “self‐poled” structure resulting from the confined growth process. Self‐poling is highly desirable as it negates the need for high electric fields, mechanical stretching, and/or high temperatures typically associated with poling treatments in ferroelectric polymers, as required for piezoelectric and/or pyroelectric applications. Here, differential scanning calorimetry, infrared spectroscopy, and dielectric permittivity measurements have been presented on as‐fabricated template‐grown polyvinylidene fluoride‐trifluoroethylene nanowires, and quantitatively compared with spin‐cast films of the same composition that have been electrically poled, both before and after subsequent depoling temperature treatment. The measurements reveal remarkably similar trends between the physical properties of the as‐grown nanowires and the electrically poled film samples, providing insight into the material structure of the “self‐poled” nanowires. In addition, piezoresponse force microscopy data are presented that allow for unambiguous identification of self‐poling in ferroelectric polymer nanostructures. Our results indicate the suitability of the template‐wetting approach in fabricating nanowires that can be used directly for piezoelectric/pyroelectric applications, without the need for post‐deposition poling/processing.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ferroelectric polymer nanowires grown using a template‐wetting method are shown to achieve an orientated “self‐poled” structure resulting from the confined growth process. Self‐poling is highly desirable as it negates the need for high electric fields, mechanical stretching, and/or high temperatures typically associated with poling treatments in ferroelectric polymers, as required for piezoelectric and/or pyroelectric applications. Here, differential scanning calorimetry, infrared spectroscopy, and dielectric permittivity measurements have been presented on as‐fabricated template‐grown polyvinylidene fluoride‐trifluoroethylene nanowires, and quantitatively compared with spin‐cast films of the same composition that have been electrically poled, both before and after subsequent depoling temperature treatment. The measurements reveal remarkably similar trends between the physical properties of the as‐grown nanowires and the electrically poled film samples, providing insight into the material structure of the “self‐poled” nanowires. In addition, piezoresponse force microscopy data are presented that allow for unambiguous identification of self‐poling in ferroelectric polymer nanostructures. Our results indicate the suitability of the template‐wetting approach in fabricating nanowires that can be used directly for piezoelectric/pyroelectric applications, without the need for post‐deposition poling/processing.
173.
Rhodri Mansell Tarun Vemulkar, Amalio Fernández-Pacheco; Cowburn, Richard P
Toward flexible spintronics: Perpendicularly magnetized synthetic antiferromagnetic thin films and nanowires on polyimide substrates Journal Article
In: Advanced Functional Materials, vol. 26, no. 26, pp. 4704–4711, 2016.
@article{vemulkar2016toward,
title = {Toward flexible spintronics: Perpendicularly magnetized synthetic antiferromagnetic thin films and nanowires on polyimide substrates},
author = {Tarun Vemulkar, Rhodri Mansell, Amalio Fernández-Pacheco and Richard P Cowburn},
url = {https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.201505138},
year = {2016},
date = {2016-01-01},
journal = {Advanced Functional Materials},
volume = {26},
number = {26},
pages = {4704--4711},
abstract = {The successful fabrication of ultra‐thin films of CoFeB/Pt with strong perpendicular magnetic anisotropy and antiferromagnetic interfacial interlayer coupling on flexible polyimide substrates is demonstrated. Despite an increased surface roughness and defect density on the polyimide substrate, magnetic single layers of CoFeB still show sharp coercive switching. Magnetic Kerr imaging shows that the magnetization reversal is dominated by a greater density of nucleation sites than the identical film grown on Si. These layers maintain their magnetic characteristics down to a radius of curvature of 350 ± µm. Further, antiferromagnetically (AF) Ruderman‐Kittel‐Kasuya‐Yoshida (RKKY) coupled bilayers of CoFeB were fabricated which are robust under bending and the coupling strength is successfully modulated via interlayer engineering. Finally, a perpendicular synthetic antiferromagnetic (SAF) thin film grown on a polyimide substrate is patterned into straight 10 µm long nanowires down to 210 nm in width that displayed the robust switching characteristics of the thin film. These are extremely promising results for the fabrication of robust, flexible, magneto‐electronic, non‐volatile memory, logic, and sensor devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The successful fabrication of ultra‐thin films of CoFeB/Pt with strong perpendicular magnetic anisotropy and antiferromagnetic interfacial interlayer coupling on flexible polyimide substrates is demonstrated. Despite an increased surface roughness and defect density on the polyimide substrate, magnetic single layers of CoFeB still show sharp coercive switching. Magnetic Kerr imaging shows that the magnetization reversal is dominated by a greater density of nucleation sites than the identical film grown on Si. These layers maintain their magnetic characteristics down to a radius of curvature of 350 ± µm. Further, antiferromagnetically (AF) Ruderman‐Kittel‐Kasuya‐Yoshida (RKKY) coupled bilayers of CoFeB were fabricated which are robust under bending and the coupling strength is successfully modulated via interlayer engineering. Finally, a perpendicular synthetic antiferromagnetic (SAF) thin film grown on a polyimide substrate is patterned into straight 10 µm long nanowires down to 210 nm in width that displayed the robust switching characteristics of the thin film. These are extremely promising results for the fabrication of robust, flexible, magneto‐electronic, non‐volatile memory, logic, and sensor devices.