Developing novel photonic nanomaterials inspired by photosynthetic biomembranes
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
Photosynthesis is essential for life on Earth and a source of great inspiration for the design of new optically-active materials [1]. "Light-harvesting" (LH) proteins found in plant chloroplasts absorb photons of light using a network of coordinated pigment molecules (e.g. chlorophylls). Energy absorbed is transferred between LH proteins, which act collectively as a satellite dish for energy trapping with remarkable quantum efficiency [2]. Yet, they are inherently limited by lack of stability of proteins and limited wavelength range of light absorbed. Novel systems with enhanced optical properties and greater stability can be designed by interfacing LH proteins with non-natural nanomaterials [3].
This PhD project will investigate the potential for integrating nanomaterials, such as lipid dyes and quantum dots, with photosynthetic systems. LH proteins and lipids will be used as building blocks and combined with a range of nanomaterials to generate modular biomembrane systems with an enhanced absorption range. You will use absorption and fluorescence spectroscopy and graphical analysis to quantify the efficiency of energy transfer, showing the improvement over the protein alone. The micro- and nanoscale organization of such LH systems can be controlled with surface patterning techniques and characterized with atomic force and fluorescence microscopy. Objectives include: (i) proof-of-concept demonstration of a bio/hybrid system with high efficiency energy transfer, (ii) micro-patterning these LH membranes on solid surfaces, (iii) exploring applications for novel chip-based devices. This project is suitable for applicants with an interest in biophysics, biochemistry, or nanoscience.
This PhD project will investigate the potential for integrating nanomaterials, such as lipid dyes and quantum dots, with photosynthetic systems. LH proteins and lipids will be used as building blocks and combined with a range of nanomaterials to generate modular biomembrane systems with an enhanced absorption range. You will use absorption and fluorescence spectroscopy and graphical analysis to quantify the efficiency of energy transfer, showing the improvement over the protein alone. The micro- and nanoscale organization of such LH systems can be controlled with surface patterning techniques and characterized with atomic force and fluorescence microscopy. Objectives include: (i) proof-of-concept demonstration of a bio/hybrid system with high efficiency energy transfer, (ii) micro-patterning these LH membranes on solid surfaces, (iii) exploring applications for novel chip-based devices. This project is suitable for applicants with an interest in biophysics, biochemistry, or nanoscience.
Publications
Hancock AM
(2022)
Enhancing the spectral range of plant and bacterial light-harvesting pigment-protein complexes with various synthetic chromophores incorporated into lipid vesicles.
in Journal of photochemistry and photobiology. B, Biology
Hancock AM
(2021)
Ultrafast energy transfer between lipid-linked chromophores and plant light-harvesting complex II.
in Physical chemistry chemical physics : PCCP
Meredith SA
(2021)
Model Lipid Membranes Assembled from Natural Plant Thylakoids into 2D Microarray Patterns as a Platform to Assess the Organization and Photophysics of Light-Harvesting Proteins.
in Small (Weinheim an der Bergstrasse, Germany)
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509681/1 | 01/10/2016 | 30/09/2021 | |||
| 1807029 | Studentship | EP/N509681/1 | 01/10/2016 | 30/06/2020 | Ashley Hancock |
| Description | During the course of this award a system has been developed which utilised model lipid membranes as a framework to allow the effective absorption range of the photosynthetic protein LHCII to be enhanced by a synthetic lipid-tethered dye. This work has been published as a communication article in the scientific journal Nanoscale, the abstract of the paper is included below and the full paper can be found with the doi: https://doi.org/10.1039/C9NR04653D Bio-hybrid nanomaterials have great potential for combining the most desirable aspects of biomolecules and the contemporary concepts of nanotechnology to create highly efficient light-harvesting materials. Light-harvesting proteins are optimized to absorb and transfer solar energy with remarkable efficiency but have a spectral range that is limited by their natural pigment complement. Herein, we present the development of model membranes ("proteoliposomes") in which the absorption range of the membrane protein Light-Harvesting Complex II (LHCII) is effectively enhanced by the addition of lipid-tethered Texas Red (TR) chromophores. Energy transfer from TR to LHCII is observed with up to 94% efficiency and increased LHCII fluorescence of up to three-fold when excited in the region of lowest natural absorption. The new self-assembly procedure offers the modularity to control the concentrations incorporated of TR and LHCII, allowing energy transfer and fluorescence to be tuned. Fluorescence Lifetime Imaging Microscopy provides single-proteoliposome-level quantification of energy transfer efficiency and confirms that functionality is retained on surfaces. Designer proteoliposomes could act as a controllable light-harvesting nanomaterial and are a promising step in the development of bio-hybrid light-harvesting systems. The second part of this research project focused on gaining a deeper understanding of the dynamics of energy transfer between the lipid-tagged dyes and light-harvesting protein. In a combined effort alongside UK based and international collaborators, we further investigated the energy transfer via ultrafast spectroscopy measurements and molecular dynamics simulations. This work has been published as an article in the scientific journal PCCP, the abstract of the paper is included below and the full paper can be found with the doi: https://doi.org/10.1039/D1CP01628H Light-Harvesting Complex II (LHCII) is a membrane protein found in plant chloroplasts that has the crucial role of absorbing solar energy and subsequently performing excitation energy transfer to the reaction centre subunits of Photosystem II. LHCII provides strong absorption of blue and red light, however, it has minimal absorption in the green spectral region where solar irradiance is maximal. In a recent proof-of-principle study, we enhanced the absorption in this spectral range by developing a biohybrid system where LHCII proteins together with lipid-linked Texas Red (TR) chromophores were assembled into lipid membrane vesicles. The utility of these systems was limited by significant LHCII quenching due to protein-protein interactions and heterogeneous lipid structures. Here, we organise TR and LHCII into a lipid nanodisc, which provides a homogeneous, well-controlled platform to study the interactions between TR molecules and single LHCII complexes. Fluorescence spectroscopy determined that TR-to-LHCII energy transfer has an efficiency of at least 60%, resulting in a 262% enhancement of LHCII fluorescence in the 525-625 nm range, two-fold greater than in the previous system. Ultrafast transient absorption spectroscopy revealed two time constants of 3.7 and 128 ps for TR-to-LHCII energy transfer. Structural modelling and theoretical calculations indicate that these timescales correspond to TR-lipids that are loosely- or tightly-associated with the protein, respectively, with estimated TR-to-LHCII separations of ~3.5 nm and ~1 nm. Overall, we demonstrate that a nanodisc-based biohybrid system provides an idealised platform to explore the photophysical interactions between extrinsic chromophores and membrane proteins with potential applications in understanding more complex natural or artificial photosynthetic systems. |
| Exploitation Route | This research represents a step forward in the development of bio-hybrid energy-absorbing nanomaterials with potential future application in bio-hybrid solar cells. |
| Sectors | Energy,Manufacturing, including Industrial Biotechology |
| URL | https://doi.org/10.1039/C9NR04653D |
| Title | Dataset for the study of Ultrafast energy transfer between lipid-linked chromophores and plant Light-Harvesting Complex II |
| Description | This dataset shows the raw data, analysed data and documentation related to figures and tables from the study "Ultrafast energy transfer between lipid-linked chromophores and plant Light-Harvesting Complex II". This includes: absorbance and fluorescence spectra; molecular dynamics images and associated files; calculations of excitation energy transfer; other graphical analyses; tabulated numerical data. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2021 |
| Provided To Others? | Yes |
| Impact | Publication in the journal PCCP (DOI - 10.1039/D1CP01628H). |
| URL | https://archive.researchdata.leeds.ac.uk/885/ |
| Title | Dataset for the study of proteoliposomes as energy-transferring materials: enhancing the spectral range of light-harvesting proteins using lipid-linked chromophores |
| Description | This dataset shows the raw data, analysed data and documentation related to figures and tables from the study "Proteoliposomes as energy transferring nanomaterials: enhancing the spectral range of light-harvesting proteins using lipid-linked chromophores". This includes: absorbance and fluorescence spectra; images from fluorescence microscopy; analysis of fitting of fluorescence spectroscopy data (FLIM); other graphical analyses; tabulated numerical data. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2019 |
| Provided To Others? | Yes |
| Impact | Publication in the journal Nanoscale. |
| URL | http://archive.researchdata.leeds.ac.uk/556/ |
| Description | Collaboration between Morigaki group in Kobe and Adams-Evans groups in Leeds |
| Organisation | Kobe University |
| Country | Japan |
| Sector | Academic/University |
| PI Contribution | Securing funding from Royal Society with collaborator Dr Kenichi Morigaki (Univ Kobe) - IEC\R3\183029 - International Exchanges 2018 Cost Share (Japan). Performing research to characterize samples sent from Japan to Leeds: optical spectroscopy and microscopy, atomic force microscopy. Generating new and improved samples in Leeds. Transfer of knowledge and expertise to Kobe. Hosted our collaborators in Leeds for one research visit of and undertaken one research visit to Japan. More planned. |
| Collaborator Contribution | Collaborator is Dr Kenichi Morigaki (Univ Kobe). Jointly securing funding from Royal Society - IEC\R3\183029 - International Exchanges 2018 Cost Share (Japan). Preparing samples in Kobe to send to Leeds. Transfer of knowledge and expertise to Leeds. Reciprocal visits. |
| Impact | Completion of one study that was published in 2021: "Model Lipid Membranes Assembled from Natural Plant Thylakoids into 2D Microarray Patterns as a Platform to Assess the Organization and Photophysics of Light-Harvesting Proteins" (DOI - 10.1002/smll.202006608). Multi-disciplinary between chemistry, biology and physics. |
| Start Year | 2019 |
| Description | Collaboration between Schlau-Cohen group in MIT and Adams group in Leeds |
| Organisation | Massachusetts Institute of Technology |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | Preparation and analysis of biological samples and shipping these to our collaborators at MIT. Data analysis and discussions. Securing seed funding from our University for travel for our initial visit to Boston. |
| Collaborator Contribution | Performing ultrafast spectroscopy experiments on samples generated in Leeds. Data analysis and discussions. |
| Impact | Completion of one study that was published in 2021: "Ultrafast energy transfer between lipid-linked chromophores and plant light-harvesting complex II" (DOI - 10.1039/D1CP01628H). Multi-disciplinary between chemistry, biology and physics. |
| Start Year | 2019 |