Dielectric polarization properties of biological molecules on the nanoscale

This research will develop new nanoscale tools for in situ measurement and imaging of the dielectric
polarization properties of biomolecules on the molecular scale. These properties are fundamental physical properties remained unknown so far owing. The lack of information is for great difficulties in measuring a dielectric response on such a small scale. Standard tools are limited to the micrometer scale and, therefore, are unable to access such information. In the last years, the supervisor pioneered scanning dielectric microscopy (SDM), a novel technique able to measure the dielectric properties of nano-objects as small as few tens of nanometers - a resolution unparalleled world-wide [1-3]. The grand challenge is now to further push the boundaries of this technique and probe the polarizability of biomolecules, in particular the molecules of Life (water, DNA, proteins) on the molecular scale, which is the aim of this research. The dielectric properties of these molecules are urgently needed to understand electrostatic interactions which underpin crucial phenomena such as molecular solvation, hydration, structuring and functionalities.

The objective of this research will be achieved by building on the previous work of the supervisor, in which she measured for the first time the dielectric constant of DNA condensed inside a virus [2] and of water confined inside two-dimensional (2D) nanochannels [3]. Specifically novel SDM setups will be pursued to increase the sensitivity of the technique and probe the dielectric properties of single biomolecules. The student will help developing the required tools and apply them to study of the dielectric properties of the macromolecules with the help of the supervisor.

This research is groundbreaking and strongly interdisciplinary, bringing together experimental and theoretical physics, physical chemistry, molecular biology and two new technologies of nanoscience: scanning dielectric microscopy, which the supervisor pioneered, and the 2D-materials technology of the Condensed Matter Group and National Graphene Institute of the University of Manchester.

The experimental information and tools that will be generated will be of major interest for academic and industrial users working in a wide range of disciplines, in particular Life sciences (biophysics, molecular biology and biomedicine), surface science and chemistry, both within the UK and overseas. In particular, the research will allow scientific and technological advances in areas related to health care. The dielectric polarization properties determine the molecular structure of the molecules of Life, such as DNA and protein conformations, and molecular interactions like those of DNA with clinically-important drugs. This research will allow gaining new insight on the molecular level. This in turn should lead to the development of new drugs against important diseases and of new molecular sensing technologies. This research will also allow important advances in physical sciences, improving our understanding of molecular solvation and transport under confinement, which are main issues of modern physical and colloid chemistry and of new emerging fields like nanofluidics.



References
[1] Fumagalli, L., Esteban-Ferrer, D., Cuervo, A., Carrascosa, J. L., Gomila, G. Label-free identification of single dielectric nanoparticles and viruses with ultraweak polarization forces. Nature Mater. 11, 808-816 (2012).
[2] A Cuervo, PD Dans, JL Carrascosa, M Orozco, G Gomila, L Fumagalli Direct measurement of the dielectric polarization properties of DNA Proc. Natl. Acad. Sci 111, E3624-E3630 (2014).
[3] Fumagalli, L., Esfandiar, A., Fabregas, R. , Hu, S., Ares, P., Janardanan, A., Yang, Q., Radha, B., Taniguchi, T., Watanabe, K., Gomila, G., Novoselov, K. S., Geim, A. K. Anomausly low dielectric constant of confined water. Science 360, 1339 (2018).