Vibrational Nanospectroscopy of Biosubstrate Surfaces and Molecular Films
Lead Research Organisation:
University of Cambridge
Department Name: Chemistry
Abstract
The project entails the imaging and spectroscopy of a variety of biologically/commercially relevant substrates before and after treatment with model chemical treatments relevant to hair and personal care products. These are to include treated and untreated hair and skin models, both as real substrates such as microtomed hair cross sections and model systems. The model systems to be investigated comprise but will not be limited to biolipid membranes (both as monolayers and as bilayers) composed primarily of DPPC and DPPE, which will be investigated as model lipid membrane systems relevant to both the personal care field and as fundamental academic studies.
Imaging will be carried out on the departmental Nano-IR2 instrument comprising of an atomic force microscope with associated mid IR laser (AFM-IR) for sub diffraction limited spectroscopy and spectral mapping with additional spectral mapping carried out on a confocal Raman microscope. Mapping studies aim to elucidate the localisation of different surface chemistries both on the large scale, circa 1 micron and also at the nanoscale at circa 40nm.
The structure and conformational ordering of the films is to be determined through the use of Sum Frequency Generation spectroscopy (SFG) with the ancillary usage of polarization modulation reflection adsorption spectroscopy (PMIRRAS) and attenuated total internal reflectance (ATR) spectroscopy. Further development of the ATR investigation is planned via the use of polarization modulated ATR in order to minimise the contribution from the liquid phase when studying hydrated lipid bilayer systems.
Imaging will be carried out on the departmental Nano-IR2 instrument comprising of an atomic force microscope with associated mid IR laser (AFM-IR) for sub diffraction limited spectroscopy and spectral mapping with additional spectral mapping carried out on a confocal Raman microscope. Mapping studies aim to elucidate the localisation of different surface chemistries both on the large scale, circa 1 micron and also at the nanoscale at circa 40nm.
The structure and conformational ordering of the films is to be determined through the use of Sum Frequency Generation spectroscopy (SFG) with the ancillary usage of polarization modulation reflection adsorption spectroscopy (PMIRRAS) and attenuated total internal reflectance (ATR) spectroscopy. Further development of the ATR investigation is planned via the use of polarization modulated ATR in order to minimise the contribution from the liquid phase when studying hydrated lipid bilayer systems.
People |
ORCID iD |
| Michael Casford (Primary Supervisor) | |
| Alexander Fellows (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/R511870/1 | 01/10/2017 | 30/09/2023 | |||
| 2110577 | Studentship | EP/R511870/1 | 01/10/2018 | 30/09/2022 | Alexander Fellows |
| Description | The funding for this work has enabled the study of several different biological substrates with nanoscale surface spectroscopy. Traditionally, spectroscopies that are commonly employed are either bulk techniques (thus not yielding any surface information) or are restricted by the diffraction limit of light - resulting in achievable resolutions only down to the micron scale in the IR region. However, the techniques of AFM-IR, which combines IR spectroscopy with an ultra-sharp tip, and SFG, which achieves pure surface spectra with sensitivity well under a monolayer, have enabled massive advances in chemical investigations of surfaces. In this work, specifically, biological substrates such as hair, red blood cells, and artificial cell membranes, have been probed to elucidate their chemical structure at unprecedented resolutions. The internal structure of hair has been well studied, but the conclusions relating to the chemical structures of the different components have always been indirectly inferred. AFM-IR, however, has allowed us to map the internal components and intrinsically determine chemical differences at a nanometre scale resolution. Similarly, AFM-IR and SFG analysis on the membranes of red blood cells from sickle cell disease patients showed clear links between localised oxidative stress in the membrane and changes to its adhesive properties - a defining issue for vaso occlusion crises. Further development of these methods are ongoing in order to improve the abilities for chemically elucidating biological surfaces. |
| Exploitation Route | The outcomes of this funding are of particular significance to others in two ways. Firstly, the work done through this funding has further demonstrated the capabilities of AFM-IR and SFG spectroscopies, particularly in the biological fields. This will, therefore, broaden the interest in these techniques to other researchers and will enable them to achieve similarly unprecedented chemical analysis of biological substrates. Furthermore, the individual findings from specific applications of these techniques such as: the chemical structure of hair, the role of oxidative stress in sickle cell disease, as well as the development of these methods for alternative uses will both assist in furthering the research within these areas and be of potential interest in health and cosmetics industries. |
| Sectors | Chemicals,Education,Healthcare,Other |
| Description | Biophysical Society Annual Meeting 2020 |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presented research at the Biophysical Society Annual Meeting 2020 (San Diego, USA) and attended many other presentations and industrial workshops. This drove discussions with researchers from other institutions around the world to progress our ideas forward. There were also useful talks and demonstrations from industrial partners to show their recent developments in instrumentation. |
| Year(s) Of Engagement Activity | 2020 |
| URL | https://www.biophysics.org/2020meeting#/ |
| Description | EFNS Conference |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Presented research at the European Forum on Nanoscale IR Spectroscopy in both 2018 (NPL, London, UK) and 2019 (University of Amsterdam, Amsterdam, NL). These events, hosted by Bruker (manufacturer of AFM-IR), brought together many users of the AFM-IR system to discuss several different applications in research, thus diversifying and broadening the impact of this relatively new technique. |
| Year(s) Of Engagement Activity | 2018,2019 |
| URL | https://www.anasysinstruments.com/efns2018/ |