Publications
129 results found
Flavell W, Neophytou A, Demetriadou A, et al., 2023, Programmed Self-Assembly of Single Colloidal Gyroids for Chiral Photonic Crystals., Adv Mater, Vol: 35
Gyroid structures are of extensive interest because they provide a rich platform for chiroptics as well as topological photonics. While the double-gyroid morphology as a bicontinuous structure is not uncommon in self-assembled soft materials, direct self-assembly of single-network gyroids has proven elusive. Here, an enantiomorphic pair of single-gyroid crystals comprising colloidal spheres is presented, and two distinct routes are demonstrated for programmed self-assembly of each single colloidal gyroid enantiomorph from rationally designed patchy spheres. The designer colloidal patchy spheres, which closely hew to their synthetic feasibility, are chiral, having either two staggered rectangular patches at opposite poles or four circular patches arranged in a well-defined geometry. The single colloidal gyroid, as well as its inverse structure, is shown to support a wide complete photonic bandgap in addition to exhibiting rich chiroptical properties, making them attractive chiral photonic crystals. The versatility of this single colloidal gyroid, the bottom-up routes devised here in silico, and the robustness of the design space for the chiral colloidal patchy spheres together make a strong case for single colloidal gyroids to supersede colloidal diamond, as a target for programmed self-assembly, in the quest for photonic crystals operating at optical frequencies.
Hamill JM, Ismael A, Al-Jobory A, et al., 2023, Quantum Interference and Contact Effects in the Thermoelectric Performance of Anthracene-Based Molecules., J Phys Chem C Nanomater Interfaces, Vol: 127, Pages: 7484-7491, ISSN: 1932-7447
We report on the single-molecule electronic and thermoelectric properties of strategically chosen anthracene-based molecules with anchor groups capable of binding to noble metal substrates, such as gold and platinum. Specifically, we study the effect of different anchor groups, as well as quantum interference, on the electric conductance and the thermopower of gold/single-molecule/gold junctions and generally find good agreement between theory and experiments. All molecular junctions display transport characteristics consistent with coherent transport and a Fermi alignment approximately in the middle of the highest occupied molecular orbital/lowest unoccupied molecular orbital gap. Single-molecule results are in agreement with previously reported thin-film data, further supporting the notion that molecular design considerations may be translated from the single- to many-molecule devices. For combinations of anchor groups where one binds significantly more strongly to the electrodes than the other, the stronger anchor group appears to dominate the thermoelectric behavior of the molecular junction. For other combinations, the choice of electrode material can determine the sign and magnitude of the thermopower. This finding has important implications for the design of thermoelectric generator devices, where both n- and p-type conductors are required for thermoelectric current generation.
Sarigamala KK, Albrecht T, Shukla S, et al., 2023, In situ interfacial nanoengineering of imidazole-bridged one-dimensional AgVO<inf>3</inf> nanoribbons by Ag fractals, Materials Today Chemistry, Vol: 27
The major bottleneck in harnessing the potential of solid-solid interfacial hetero structures involves incoherent interface constructions and complicated synthesis approaches. In this context, a synthesis strategy involving in situ interfacial manipulation of imidazole-bridged one-dimensional single-crystalline nanoribbons is developed through the dynamic growth of Ag fractals. This article successfully demonstrates structural and morphological changes in the monoclinic patterns of silver vanadate nanoribbons with Wulf constructions. These are associated with in situ electron beam perturbations and can be attributed to β-phase silver vanadate crystals. The dynamics and topological modifications induced on the nanohybrid interfaces mechanistically suggest the ability of the novel hybrid interfaces in harnessing and storing photogenerated auxiliary charge carriers. The synthesis methodology used enables in overcoming major bottleneck in nanoengineering of solid-solid interfacial heterostructures by using real-time feedback of the imaging e-beam to precisely fabricate these heterostructures and study the interface transition.
Weaver C, Fortuin AC, Vladyka A, et al., 2022, Unsupervised classification of voltammetric data beyond principal component analysis, CHEMICAL COMMUNICATIONS, Vol: 58, Pages: 10170-10173, ISSN: 1359-7345
- Author Web Link
- Cite
- Citations: 1
Wilkinson LA, Bennett TLR, Grace IM, et al., 2022, Assembly, structure and thermoelectric properties of 1,1 '-dialkynylferrocene 'hinges', CHEMICAL SCIENCE, ISSN: 2041-6520
Bennett TLR, Alshammari M, Au-Yong S, et al., 2022, Multi-component self-assembled molecular-electronic films: towards new high-performance thermoelectric systems, CHEMICAL SCIENCE, Vol: 13, Pages: 5176-5185, ISSN: 2041-6520
- Author Web Link
- Cite
- Citations: 3
Albrecht T, Cao XE, Chen D, et al., 2022, Electrochemical data mining: from information to knowledge: general discussion, FARADAY DISCUSSIONS, Vol: 233, Pages: 58-76, ISSN: 1359-6640
Albrecht T, Bohn PW, Buckingham MA, et al., 2022, State of the art energy conversion at the nanointerface: general discussion, FARADAY DISCUSSIONS, Vol: 233, Pages: 112-121, ISSN: 1359-6640
Algar WR, Albrecht T, Faulds K, et al., 2022, Analytical nanoscience, ANALYST, Vol: 147, Pages: 765-766, ISSN: 0003-2654
Hamill JM, Weaver C, Albrecht T, 2021, Multivariate Approach to Single-Molecule Thermopower and Electrical Conductance Measurements, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 125, Pages: 26256-26262, ISSN: 1932-7447
Carro P, Azofra LM, Albrecht T, et al., 2021, Unraveling the Causes of the Instability of Au-n(SR)(x) Nanoclusters on Au(111), CHEMISTRY OF MATERIALS, Vol: 33, Pages: 3428-3435, ISSN: 0897-4756
- Author Web Link
- Cite
- Citations: 2
Pensa E, Azofra LM, Albrecht T, et al., 2020, Shedding Light on the Interfacial Structure of Low-Coverage Alkanethiol Lattices, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 124, Pages: 26748-26758, ISSN: 1932-7447
- Author Web Link
- Cite
- Citations: 4
Vladyka A, Albrecht T, 2020, Unsupervised classification of single-molecule data with autoencoders and transfer learning, MACHINE LEARNING-SCIENCE AND TECHNOLOGY, Vol: 1
- Author Web Link
- Cite
- Citations: 7
Elshahawy M, Pensa E, Albrecht T, et al., 2020, Stepwise electrochemical deposition and single-molecule conductance of nucleic acid analogues, ELECTROCHIMICA ACTA, Vol: 346, ISSN: 0013-4686
Wang X, Bennett TLR, Ismael A, et al., 2020, Scale-up of room-temperature constructive quantum interference from single molecules to self-assembled molecular-electronic films, Journal of the American Chemical Society, Vol: 142, Pages: 8555-8560, ISSN: 0002-7863
The realization of self-assembled molecular-electronic films, whose room-temperature transport properties are controlled by quantum interference (QI), is an essential step in the scale-up of QI effects from single molecules to parallel arrays of molecules. Recently, the effect of destructive QI (DQI) on the electrical conductance of self-assembled monolayers (SAMs) has been investigated. Here, through a combined experimental and theoretical investigation, we demonstrate chemical control of different forms of constructive QI (CQI) in cross-plane transport through SAMs and assess its influence on cross-plane thermoelectricity in SAMs. It is known that the electrical conductance of single molecules can be controlled in a deterministic manner, by chemically varying their connectivity to external electrodes. Here, by employing synthetic methodologies to vary the connectivity of terminal anchor groups around aromatic anthracene cores, and by forming SAMs of the resulting molecules, we clearly demonstrate that this signature of CQI can be translated into SAM-on-gold molecular films. We show that the conductance of vertical molecular junctions formed from anthracene-based molecules with two different connectivities differ by a factor of approximately 16, in agreement with theoretical predictions for their conductance ratio based on CQI effects within the core. We also demonstrate that for molecules with thioether anchor groups, the Seebeck coefficient of such films is connectivity dependent and with an appropriate choice of connectivity can be boosted by ∼50%. This demonstration of QI and its influence on thermoelectricity in SAMs represents a critical step toward functional ultra-thin-film devices for future thermoelectric and molecular-scale electronics applications.
Irving OJ, Albrecht T, 2020, DNA Assay-on-a-String: Rapid Detection of Marker Panels Against Sepsis, ECS Meeting Abstracts, Vol: MA2020-01, Pages: 1966-1966
<jats:p> Sepsis is a life-threatening condition afflicting 250,000 patients in the UK alone. The condition is defined as the overstimulation of the immune system in response to an invasive microorganism, primarily bacterial infections<jats:sup>1</jats:sup>. As the condition progresses, symptoms worsen from fever and respiration difficulties to organ failure and cardiovascular issues. The primary test for sepsis is the use of blood cultures. These can take up to two days to complete and do not always provide a positive result. Whilst there have been many biomarkers identified for sepsis, few have been incorporated into the clinic. High sensitivity biomarkers include both proteomic and genetic biomarkers. In proteomic studies, interleukin 6, 8, and 10 proteins, c-reactive protein, and procalcitonin have proved to be statistically significant diagnostic markers for the disease. Two micro-RNAs have also been shown to be significant, these are miRNA-146a and miRNA-150<jats:sup>2</jats:sup>.</jats:p> <jats:p>This research is focused on the development of a new, rapid diagnostic test for sepsis utilising many different biomarkers in combination. To achieve this the DNA-assay-on-a-string technique will be utilised to bind biomarkers of interest. The resolution required to monitor this modified DNA, requires nanopipettes with a pore size of 10 nm to be used<jats:sup>3,4</jats:sup>. This was achieved by use of a p2000 pipette puller along with quartz capillary tubes. All electrodes used were Ag/AgCl and pore diameter was determined by cyclic voltammetry<jats:sup>5–7</jats:sup>. The conductance was extracted from an I-V trace and applied to a pore size calculation equation by Steinbock et.al<jats:sup>8</jats:sup>.</jats:p> <jats:p>To create a carrier for multiple biomarkers, double stranded DNA will be used as a backbone and single stranded DNA, antibod
Awais N, Rodriguez P, Albrecht T, 2020, Surface Design: Exploiting the Instability of Small Nanoparticles on Metallic Substrates, ECS Meeting Abstracts, Vol: MA2020-01, Pages: 2865-2865
<jats:p> Small metal nanoparticles (NPs) within the size range of 1-3 nm exhibit unique electronic and catalytic properties.<jats:sup>1–3</jats:sup> Thiolated nanoparticles have been shown to undergo an entropically driven redistribution of the capping layer with a Au<jats:sub>surface</jats:sub>-AuNP system. It has been postulated that different substrate and NP materials may be employed for surface design.<jats:sup>4</jats:sup> </jats:p> <jats:p>The aim of this work was to investigate surface structure modification of different substrate-NP combinations, in alkaline media and via their performance in the electro-catalytic decomposition of glycerol (GlyOH).<jats:sup>5</jats:sup> Pt<jats:sub>surface</jats:sub>-AuNP and Au<jats:sub>surface</jats:sub>-PtNP combinations were investigated, by immersion of the surfaces into solutions of the NPs. AuNPs were synthesised using a bottom-up metal reduction<jats:sup>6</jats:sup>, and PtNPs were synthesised via the cathodic corrosion method.<jats:sup>7,8</jats:sup> Electrochemical responses were measured using cyclic voltammetry (CV).</jats:p> <jats:p>Pt<jats:sub>surface</jats:sub>-AuNP resulted in a lower current response, but no change in characteristic Pt peaks within the CV profile, indicating that the AuNPs remain protected by the thiol capping layer on the Pt surface. However, Au<jats:sub>surface</jats:sub>-PtNP gave a CV displaying both Au and Pt characteristic peaks (<jats:bold>Fig. 1)</jats:bold>, suggesting there is thiol surface diffusion from the PtNPs into the bulk.</jats:p> <jats:p>1 S. Hrapovic, Y. Liu, K. B. Male and J. H. T. Luong, <jats:italic>Anal. Chem.</jats:italic>, 2004, <jats:bold>76</jats:bold>, 1083–1088.</jats:p> <ja
Yasini P, Shepard S, Albrecht T, et al., 2020, Combined Impact of Denticity and Orientation on Molecular-Scale Charge Transport, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 124, Pages: 9460-9469, ISSN: 1932-7447
- Author Web Link
- Cite
- Citations: 2
Awais N, Rodriguez P, Albrecht T, 2020, Surface Design: Exploiting the Instability of Small Nanoparticles on Metallic Substrates, ECS Transactions, Vol: 97, Pages: 885-892, ISSN: 1938-6737
Thiolated Au nanoparticles have been shown to undergo fast redistribution of the capping layer and subsequently of the metal core, when in contact with bare Au substrates. This is the result of an intricate interplay of entropic and enthalpic factors, which are likely affected by the choice of core metal and capping chemistry. This raises interesting questions, for example whether such a process could be used to modify and functionalize electrode substrates in a well-defined and controlled manner. Here, we report results for Pt and Au nanoparticles on Au and Pt substrates, based on the electrochemical response of the modified electrodes towards the oxidation of glycerol in alkaline media. Our study provides evidence that Pt nanoparticles on Au substrates remain relatively stable, while Au nanoparticles on Pt substrates readily decompose. This is in accordance with initial expectations based on the energetics of the thiol/metal bond.
Carro P, Pensa E, Albrecht T, et al., 2020, Dynamics of RS-(Au-SR)(x) Staple Motifs on Metal Surfaces: From Nanoclusters to 2D Surfaces, JOURNAL OF PHYSICAL CHEMISTRY C, Vol: 124, Pages: 5452-5459, ISSN: 1932-7447
- Author Web Link
- Cite
- Citations: 6
Caballero AB, Cardo L, Claire S, et al., 2019, Assisted delivery of anti-tumour platinum drugs using DNA-coiling gold nanoparticles bearing lumophores and intercalators: towards a new generation of multimodal nanocarriers with enhanced action, CHEMICAL SCIENCE, Vol: 10, Pages: 9244-9256, ISSN: 2041-6520
- Author Web Link
- Cite
- Citations: 10
Kubánková M, Lin X, Albrecht T, et al., 2019, Rapid fragmentation during seeded lysozyme aggregation revealed at the single molecule level, Analytical Chemistry, Vol: 91, Pages: 6880-6886, ISSN: 0003-2700
Protein aggregation is associated with neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. The poorly understood pathogenic mechanism of amyloid diseases makes early stage diagnostics or therapeutic intervention a challenge. Seeded polymerization that reduces the duration of the lag phase and accelerates fibril growth is a widespread model to study amyloid formation. Seeding effects are hypothesized to be important in the "infectivity" of amyloids and are linked to the development of systemic amyloidosis in vivo. The exact mechanism of seeding is unclear yet critical to illuminating the propagation of amyloids. Here we report on the lateral and axial fragmentation of seed fibrils in the presence of lysozyme monomers at short time scales, followed by the generation of oligomers and growth of fibrils.
Pensa E, Karpowicz R, Jabaoński A, et al., 2019, Gold-Induced Desulfurization in a Bis(ferrocenyl) Alkane Dithiol, Organometallics, ISSN: 0276-7333
© 2019 American Chemical Society. Thiol-modified ferrocenes on gold have been archetypical model systems for many fundamental charge transfer and other studies, since both thiol-gold and ferrocene redox chemistry are considered to be well-understood. Thus unexpectedly, we found that for a representative of a new class of flexibly linked bis-ferrocenyl compounds, namely, 1-10-bis(1-ferrocenyl)decane dithiol, surface immobilization on gold failed. Instead, in the presence of gold, molecular decomposition took place, resulting in sulfur-based adlayers and well-defined molecular elimination products, for which we provide spectroscopic evidence. Careful control experiments and comparison with related ferrocene compounds provide insight into the mechanism of the observed elimination reactions, as a combined effect of the molecular structure and the nature of the gold/sulfur bond. These findings, thus, have a broader impact on the design of molecular adlayers, for example, in the context of surface functionalization in sensing or the synthesis of gold nanoparticles.
Leber R, Wilson L, Robaschik P, et al., 2019, Vacuum deposition of biferrocene thin films: growth strategies for stability and tuneable magnetism, 257th National Meeting of the American-Chemical-Society (ACS), Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
Albrecht T, 2019, Single-Molecule Analysis with Solid-State Nanopores, Publisher: ANNUAL REVIEWS
- Author Web Link
- Cite
- Citations: 41
Loh AYY, Burgess CH, Tanase DA, et al., 2018, Electric single-molecule hybridization detector for short DNA fragments, Analytical Chemistry, Vol: 90, Pages: 14063-14071, ISSN: 0003-2700
By combining DNA nanotechnology and high-bandwidth single-molecule detection in nanopipets, we demonstrate an electric, label-free hybridization sensor for short DNA sequences (<100 nucleotides). Such short fragments are known to occur as circulating cell-free DNA in various bodily fluids, such as blood plasma and saliva, and have been identified as disease markers for cancer and infectious diseases. To this end, we use as a model system an 88-mer target from the RV1910c gene in Mycobacterium tuberculosis, which is associated with antibiotic (isoniazid) resistance in TB. Upon binding to short probes attached to long carrier DNA, we show that resistive-pulse sensing in nanopipets is capable of identifying rather subtle structural differences, such as the hybridization state of the probes, in a statistically robust manner. With significant potential toward multiplexing and high-throughput analysis, our study points toward a new, single-molecule DNA-assay technology that is fast, easy to use, and compatible with point-of-care environments.
Li B, Famili M, Pensa E, et al., 2018, Cross-plane conductance through a graphene/molecular monolayer/Au sandwich, Nanoscale, Vol: 10, Pages: 19791-19798, ISSN: 2040-3364
The functionalities offered by single-molecule electrical junctions are yet to be translated into monolayer or few-layer molecular films, where making effective and reproducible electrical contact is one of the challenging bottlenecks. Here we take a significant step in this direction by demonstrating that excellent electrical contact can be made with a monolayer biphenyl-4,4′-dithiol (BPDT) molecular film, sandwiched between gold and graphene electrodes. This sandwich device structure is advantageous, because the current flows through the molecules to the gold substrate in a ‘cross-plane’ manner, perpendicular to the plane of graphene, yielding high-conductance devices. We elucidate the nature of the cross-plane graphene/molecule/Au transport using quantum transport calculations and introduce a simple analytical model, which captures generic features of the current–voltage characteristic. Asymmetry in junction properties results from the disparity in electrode electrical properties, the alignment of the BPDT HOMO–LUMO energy levels and the specific characteristics of the graphene electrode. The experimental observation of scalability of junction properties within the junction area, in combination with a theoretical description of the transmission probability of the thiol–graphene contact, demonstrates that between 10% and 100% of the molecules make contact with the electrodes, which is several orders of magnitude greater than that achieved to date in the literature.
Loh AYY, Burgess CH, Tanase DA, et al., 2018, An all-electric single-molecule hybridisation detector for short DNA fragments, Publisher: arXiv
In combining DNA nanotechnology and high-bandwidth single-molecule detectionin nanopipettes, we demonstrate an all-electric, label-free hybridisationsensor for short DNA sequences (< 100 nt). Such short fragments are known tooccur as circulating cell-free DNA in various bodily fluids, such as bloodplasma and saliva, and have been identified as disease markers for cancer andinfectious diseases. To this end, we use as a model system a 88-mer target fromthe RV1910c gene in Mycobacterium tuberculosis that is associated withantibiotic (isoniazid) resistance in TB. Upon binding to short probes attachedto long carrier DNA, we show that resistive pulse sensing in nanopipettes iscapable of identifying rather subtle structural differences, such as thehybridisation state of the probes, in a statistically robust manner. Withsignificant potential towards multiplexing and high-throughput analysis, ourstudy points towards a new, single-molecule DNA assay technology that is fast,easy to use and compatible with point of care environments.
Al-Zubeidi A, Godfrey D, Albrecht T, 2018, Disentangling chemical effects in ionic-liquid-based Cu leaching from chalcopyrite, JOURNAL OF ELECTROANALYTICAL CHEMISTRY, Vol: 819, Pages: 130-135, ISSN: 1572-6657
- Author Web Link
- Cite
- Citations: 7
Milan DC, Al-owaedi O, Bock S, et al., 2018, Insulated molecular wires: Inhibiting orthogonal contacts in metal complex, 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, Publisher: AMER CHEMICAL SOC, ISSN: 0065-7727
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.