LCN Lunch-and-Learn Seminar: Dr David Ayuso

Title: Twisting light in 3D for small-molecule chiral sensing and manipulation

Abstract: Apart from their well-established roles in nanotechnology or drug discovery, small chiral molecules are emerging as biomarkers for early-stage diagnosis, prognosis, and personalised medicine [1]. For instance, small variations in the concentration of D-serine in biofluids containing a large excess of L-serine have been correlated to Alzheimer’s disease. However, current optical methods lack the sensitivity to detect such tiny differences because circularly polarised light does not fit the size of a small molecule, whereas chemical approaches (e.g. liquid chromatography) are not sufficiently rapid or cost-effective.

In this seminar, I will show how we can overcome these limitations by shaping light’s polarisation in 3D [2-5] so that the tip of the electric-field vector draws a chiral Lissajous figure in time. Such locally chiral light can drive ultrafast electronic currents inside the molecules that interact with the chiral molecular potential in a highly enantiosensitive manner, taking us from 0.1% up to 100% chiral sensitivity.

[1] Y. Liu et al, Nat Rev Chem 7, 355 (2023)

[2] D. Ayuso et al, Nat Photon 13, 866 (2019)

[3] D. Ayuso et al, Nat Commun 12, 3951 (2021)

[4] J. Vogwell et al, Science Advances 9, eadj1429 (2023)

[5] N. Mayer et al, Nat Photon 18, 1155 (2024)