We have an exiting PhD opening for a September 2019 start. Applications are open! Please get in touch.

PhD to combine nanometer resolution imaging and single molecule plasmonic sensors

Deadline: April 2019
Title: A DNA-metal nanoparticle metamaterial for improved single-molecule biosensing
Funding: RCUK level Fees & Scholarship
Apply: Online

This new PhD opportunity is a collaboration between the Soeller lab and the Vollmer lab at the Living Systems Institute.

Nanoparticles are widely used as environmental sensors in health applications, and in novel materials that catalyse reactions and produce clean energy. In these applications, it is critical to understand and control the interaction of molecules near nanoparticle surfaces. To understand the underlying mechanisms, a new approach is required, combining spatial information with readout of the rapid dynamics of many biomolecular interactions. This approach should allow the study of individual molecules so that they can be detected and monitored with extraordinary sensitivity and at the same time we want to see where these molecules are when they interact with the sensor and their molecular reaction partners.

Based on this motivation the studentship will establish a novel single-molecule imaging and sensing platform to study biomolecular interactions at nanoparticle surfaces at unprecedented spatial and temporal resolution. The combination of fluorescence imaging with single molecule sensing will enable localising (bio)molecular interactions with nanometre precision and widely adjustable read-out with nanosecond to hour time resolution. The analysis of the rich data obtained with this new methodology will enable us to develop strategies to control reaction dynamics and protein function directly at nanoparticle interfaces. In addition, the combination of DNA and gold nanoparticles constitutes a new metamaterial, i.e. a material that combines characteristics from the constituent materials (DNA and gold) in a novel way to give it entirely new properties. We will study the metamaterial properties of the DNA-gold nanoparticle composite and explore its use in biotechnology applications in collaboration with colleagues from the biosciences.

The project is a collaboration between the laboratories of Profs Soeller and Vollmer at the Living Systems Institute of the University of Exeter as well as Dr Di Michele (Cambridge). In the project, we will attach rigid DNA nanoscaffolds, known as DNA Origami, to gold nanoparticles to present reaction partners at precise distances from the particle surface. We will map reaction kinetics as a function of surface distance by placing binding sites at locations along the DNA scaffold. The new approach builds on the expertise of the Vollmer laboratory with gold nanoparticle plasmonics [1-3] and the Soeller and Di Michele laboratories’ expertise in high-resolution imaging and DNA nanotechnology [4-6].

The highly cross-disciplinary project bridging optics, biophysics, and biomaterials will be carried out at the Exeter Living Systems Institute, the ideal environment to explore future healthcare and biotechnology applications with the new technology. The candidate will receive training in single molecule biophysics, optical super-resolution imaging and single molecule sensing. The successful candidate will also make regular visits to the Di Michele Laboratory in Cambridge to advance their skills in DNA nanotechnology.

References

1. Subramanian et al. Adv Mater 2018.
2. Kim, Baaske, Vollmer. Adv Mater 2016;28:9941.
3. Baaske, Vollmer. Nat Phot 2016;10:733.
4. Lutz T, Clowsley AH, Lin R, et al. Nano Res 2018;78:993.
5. Jayasinghe I, Clowsley AH, Lin R, et al. Cell Reports 2018;22:557–67.
6. Di Michele L, Varrato F, Kotar J, et al. Nat Commun 2013;4:2007.