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Nirmalraj PN, Schneider T, Lüder L, Felbecker A. Protein fibril length in cerebrospinal fluid is increased in Alzheimer's disease. Commun Biol 2023; 6:251. [PMID: 36890343 PMCID: PMC9995532 DOI: 10.1038/s42003-023-04606-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/16/2023] [Indexed: 03/10/2023] Open
Abstract
Alzheimer's disease (AD) associated proteins exist in cerebrospinal fluid (CSF). This paper evidences that protein aggregate morphology distinctly differs in CSF of patients with AD dementia (ADD), mild cognitive impairment due to AD (MCI AD), with subjective cognitive decline without amyloid pathology (SCD) and with non-AD MCI using liquid-based atomic force microscopy (AFM). Spherical-shaped particles and nodular-shaped protofibrils were present in the CSF of SCD patients, whereas CSF of ADD patients abundantly contained elongated mature fibrils. Quantitative analysis of AFM topographs confirms fibril length is higher in CSF of ADD than in MCI AD and lowest in SCD and non-AD dementia patients. CSF fibril length is inversely correlated with CSF amyloid beta (Aβ) 42/40 ratio and CSF p-tau protein levels (obtained from biochemical assays) to predict amyloid and tau pathology with an accuracy of 94% and 82%, respectively, thus identifying ultralong protein fibrils in CSF as a possible signature of AD pathology.
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Affiliation(s)
- Peter Niraj Nirmalraj
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, CH-8600, Switzerland.
| | - Thomas Schneider
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, CH-9007, Switzerland
| | - Lars Lüder
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, CH-8600, Switzerland
| | - Ansgar Felbecker
- Department of Neurology, Cantonal Hospital St. Gallen, St. Gallen, CH-9007, Switzerland.
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Nirmalraj PN, List J, Battacharya S, Howe G, Xu L, Thompson D, Mayer M. Complete aggregation pathway of amyloid β (1-40) and (1-42) resolved on an atomically clean interface. SCIENCE ADVANCES 2020; 6:eaaz6014. [PMID: 32285004 PMCID: PMC7141833 DOI: 10.1126/sciadv.aaz6014] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/14/2020] [Indexed: 05/22/2023]
Abstract
To visualize amyloid β (Aβ) aggregates requires an uncontaminated and artifact-free interface. This paper demonstrates the interface between graphene and pure water (verified to be atomically clean using tunneling microscopy) as an ideal platform for resolving size, shape, and morphology (measured by atomic force microscopy) of Aβ-40 and Aβ-42 peptide assemblies from 0.5 to 150 hours at a 5-hour time interval with single-particle resolution. After confirming faster aggregation of Aβ-42 in comparison to Aβ-40, a stable set of oligomers with a diameter distribution of ~7 to 9 nm was prevalently observed uniquely for Aβ-42 even after fibril appearance. The interaction energies between a distinct class of amyloid aggregates (dodecamers) and graphene was then quantified using molecular dynamics simulations. Last, differences in Aβ-40 and Aβ-42 networks were resolved, wherein only Aβ-42 fibrils were aligned through lateral interactions over micrometer-scale lengths, a property that could be exploited in the design of biofunctional materials.
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Affiliation(s)
- Peter Niraj Nirmalraj
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
- Transport at Nanoscale Interfaces Laboratory, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf CH-8600, Switzerland
- Corresponding author.
| | - Jonathan List
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
| | - Shayon Battacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Geoffrey Howe
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94T9PX, Ireland
| | - Michael Mayer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, CH-1700 Fribourg, Switzerland
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Inkpen MS, Leroux YR, Hapiot P, Campos LM, Venkataraman L. Reversible on-surface wiring of resistive circuits. Chem Sci 2017; 8:4340-4346. [PMID: 28660061 PMCID: PMC5472029 DOI: 10.1039/c7sc00599g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 04/05/2017] [Indexed: 01/04/2023] Open
Abstract
Whilst most studies in single-molecule electronics involve components first synthesized ex situ, there is also great potential in exploiting chemical transformations to prepare devices in situ. Here, as a first step towards this goal, we conduct reversible reactions on monolayers to make and break covalent bonds between alkanes of different lengths, then measure the conductance of these molecules connected between electrodes using the scanning tunneling microscopy-based break junction (STM-BJ) method. In doing so, we develop the critical methodology required for assembling and disassembling surface-bound single-molecule circuits. We identify effective reaction conditions for surface-bound reagents, and importantly demonstrate that the electronic characteristics of wires created in situ agree with those created ex situ. Finally, we show that the STM-BJ technique is unique in its ability to definitively probe surface reaction yields both on a local (∼50 nm2) and pseudo-global (≥10 mm2) level. This investigation thus highlights a route to the construction and integration of more complex, and ultimately functional, surface-based single-molecule circuitry, as well as advancing a methodology that facilitates studies beyond the reach of traditional ex situ synthetic approaches.
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Affiliation(s)
- Michael S Inkpen
- Department of Applied Physics and Applied Mathematics , Columbia University , New York , NY 10027 , USA . ;
- Institut des Sciences Chimiques de Rennes (Equipe MaCSE) , CNRS , Université de Rennes 1 , Campus de Beaulieu, Bat 10C , Rennes Cedex , UMR 6226 , France
| | - Yann R Leroux
- Institut des Sciences Chimiques de Rennes (Equipe MaCSE) , CNRS , Université de Rennes 1 , Campus de Beaulieu, Bat 10C , Rennes Cedex , UMR 6226 , France
| | - Philippe Hapiot
- Institut des Sciences Chimiques de Rennes (Equipe MaCSE) , CNRS , Université de Rennes 1 , Campus de Beaulieu, Bat 10C , Rennes Cedex , UMR 6226 , France
| | - Luis M Campos
- Department of Chemistry , Columbia University , New York , NY 10027 , USA
| | - Latha Venkataraman
- Department of Applied Physics and Applied Mathematics , Columbia University , New York , NY 10027 , USA . ;
- Department of Chemistry , Columbia University , New York , NY 10027 , USA
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Nirmalraj P, Daly R, Martin N, Thompson D. Motion of Fullerenes around Topological Defects on Metals: Implications for the Progress of Molecular Scale Devices. ACS APPLIED MATERIALS & INTERFACES 2017; 9:7897-7902. [PMID: 28233982 DOI: 10.1021/acsami.7b00408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Research on motion of molecules in the presence of thermal noise is central for progress in two-terminal molecular scale electronic devices. However, it is still unclear what influence imperfections in bottom metal electrode surface can have on molecular motion. Here, we report a two-layer crowding study, detailing the early stages of surface motion of fullerene molecules on Au(111) with nanoscale pores in a n-tetradecane chemical environment. The motion of the fullerenes is directed by crowding of the underlying n-tetradecane molecules around the pore fringes at the liquid-solid interface. We observe in real-space the growth of molecular populations around different pore geometries. Supported by atomic-scale modeling, our findings extend the established picture of molecular crowding by revealing that trapped solvent molecules serve as prime nucleation sites at nanopore fringes.
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Affiliation(s)
- Peter Nirmalraj
- IBM Research-Zurich , Säumerstrasse 4, CH- 8803 Rüschlikon, Switzerland
| | - Ronan Daly
- Department of Engineering, University of Cambridge , 17 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Nazario Martin
- Departmento de Quimica Organica, Facultad de Quimica, Universidad Complutense de Madrid , E-28040 Madrid, Spain
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick , Limerick V94 T9PX, Ireland
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Fingerprinting Electronic Molecular Complexes in Liquid. Sci Rep 2016; 6:19009. [PMID: 26743542 PMCID: PMC4705545 DOI: 10.1038/srep19009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 12/02/2015] [Indexed: 01/14/2023] Open
Abstract
Predicting the electronic framework of an organic molecule under practical conditions is essential if the molecules are to be wired in a realistic circuit. This demands a clear description of the molecular energy levels and dynamics as it adapts to the feedback from its evolving chemical environment and the surface topology. Here, we address this issue by monitoring in real-time the structural stability and intrinsic molecular resonance states of fullerene (C60)-based hybrid molecules in the presence of the solvent. Energetic levels of C60 hybrids are resolved by in situ scanning tunnelling spectroscopy with an energy resolution in the order of 0.1 eV at room-temperature. An ultra-thin organic spacer layer serves to limit contact metal-molecule energy overlap. The measured molecular conductance gap spread is statistically benchmarked against first principles electronic structure calculations and used to quantify the diversity in electronic species within a standard population of molecules. These findings provide important progress towards understanding conduction mechanisms at a single-molecular level and in serving as useful guidelines for rational design of robust nanoscale devices based on functional organic molecules.
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Nirmalraj PN, Thompson D, Riel HE. Capturing the embryonic stages of self-assembly - design rules for molecular computation. Sci Rep 2015; 5:10116. [PMID: 25960364 PMCID: PMC4650799 DOI: 10.1038/srep10116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/30/2015] [Indexed: 12/12/2022] Open
Abstract
The drive towards organic computing is gaining momentum. Interestingly, the building blocks for such architectures is based on molecular ensembles extending from nucleic acids to synthetic molecules. Advancement in this direction requires devising precise nanoscopic experiments and model calculations to decipher the mechanisms governing the integration of a large number of molecules over time at room-temperature. Here, we report on ultrahigh-resolution scanning tunnelling microscopic measurements to register the motion of molecules in the absence of external stimulus in liquid medium. We observe the collective behavior of individual molecules within a swarm which constantly iterate their position to attain an energetically favourable site. Our approach provides a consistent pathway to register molecular self-assembly in sequential steps from visualising thermodynamically driven repair of defects up until the formation of a stable two-dimensional configuration. These elemental findings on molecular surface dynamics, self-repair and intermolecular kinetic pathways rationalised by atom-scale simulations can be explored for developing new models in algorithmic self-assembly to realisation of evolvable hardware.
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Affiliation(s)
| | - Damien Thompson
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Ireland
| | - Heike E. Riel
- IBM Research–Zurich, Säumerstrasse 4, CH- 8803, Rüschlikon, Switzerland
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Nirmalraj P, Thompson D, Molina-Ontoria A, Sousa M, Martín N, Gotsmann B, Riel H. Nanoelectrical analysis of single molecules and atomic-scale materials at the solid/liquid interface. NATURE MATERIALS 2014; 13:947-953. [PMID: 25129620 DOI: 10.1038/nmat4060] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 07/15/2014] [Indexed: 06/03/2023]
Abstract
Evaluating the built-in functionality of nanomaterials under practical conditions is central for their proposed integration as active components in next-generation electronics. Low-dimensional materials from single atoms to molecules have been consistently resolved and manipulated under ultrahigh vacuum at low temperatures. At room temperature, atomic-scale imaging has also been performed by probing materials at the solid/liquid interface. We exploit this electrical interface to develop a robust electronic decoupling platform that provides precise information on molecular energy levels recorded using in situ scanning tunnelling microscopy/spectroscopy with high spatial and energy resolution in a high-density liquid environment. Our experimental findings, supported by ab initio electronic structure calculations and atomic-scale molecular dynamics simulations, reveal direct mapping of single-molecule structure and resonance states at the solid/liquid interface. We further extend this approach to resolve the electronic structure of graphene monolayers at atomic length scales under standard room-temperature operating conditions.
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Affiliation(s)
- Peter Nirmalraj
- IBM Research-Zurich, Säumerstrasse 4 8803 Rüschlikon, Switzerland
| | - Damien Thompson
- 1] Department of Physics and Energy, University of Limerick, Ireland [2] Materials and Surface Science Institute, University of Limerick, Ireland
| | - Agustín Molina-Ontoria
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, 28049 Madrid, Spain
| | - Marilyne Sousa
- IBM Research-Zurich, Säumerstrasse 4 8803 Rüschlikon, Switzerland
| | - Nazario Martín
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), Cantoblanco, 28049 Madrid, Spain
| | - Bernd Gotsmann
- IBM Research-Zurich, Säumerstrasse 4 8803 Rüschlikon, Switzerland
| | - Heike Riel
- IBM Research-Zurich, Säumerstrasse 4 8803 Rüschlikon, Switzerland
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