Engineering Chirality of Materials for a Healthier Future by Assistant Prof Prashant Kumar

The Discovery Science Seminar, hosted by IAS in collaboration with the Graduate Students’ Clubs of MAE, MSE and SPMS on 22 January 2025, featured a profound talk by Assistant Prof Prashant Kumar (MSE NTU) titled "Engineering Chirality of Materials for a Healthier Future”.

Chirality is a recurring concept in many branches of science, describing whether an object is identical to its mirror image. A ‘chiral’ object can never be superimposed with its mirror image through any rotation or translation, much like a pair of human hands that cannot overlap. Most amino acids that make up the proteins in all living organisms on Earth exhibit chirality, meaning that an amino acid molecule and its mirror image can have completely different functions. As a result, designing and controlling such chiral structures at the nanoscale is rapidly emerging as a field with important applications in biomedicine.

Asst Prof Kumar has achieved significant milestones in nanomaterials research, which earned him a spot among the 35 Innovators Under 35 by MIT Technology Review for the Asia-Pacific region in 2024. During the seminar, he presented his work on the synthesis and characterisation of chiral nanomaterials.

While the past decade has seen significant progress in synthesising nanomaterials with chiral structures, there has been a notable absence of the study of their tunability. In this context, Asst Prof Kumar and his team synthesise and study materials that can be continuously tuned in size and handedness.

Created by mixing aqueous solutions of cadmium ions with L or D-cystine amino acids, the new material was found to consist of microscopic twisted bowtie structures. Further high-resolution scans with an electron microscope revealed that these bowties are composed of nanosheets, and X-ray diffraction was used to determine the unit-cell structure. He also investigated the optical response of this new material to circularly polarised light and found a match between the resulting spectrum and numerical simulations.

Asst Prof Kumar sharing his insights on the synthesis and characterisation of chiral nanomaterials.

The size and twist of these bowties are largely dependent on electrostatic interactions between the molecules, which are governed by the initial concentration of cadmium ions and the pH levels. By carefully adjusting these parameters, Asst Prof  Kumar was able to synthesise a family of twisted bowties with varying sizes and handedness. This high level of controllability allow him to synthesise these materials on demand, depending on the required optical responsivity.

This technique of tuning the size of nanoparticles also inspired Asst Prof  Kumar to interface them with biomolecules. By specifically designing the geometry of inorganic nanoparticles, he was able to bind them to the SARS-CoV-2 virus, rendering it inert. To test the efficacy of this method, he administered the nanoparticles to infected mice and observed complete inhibition of the virus within days.

Engaging Q&A session.

Asst Prof  Kumar and his team's work opens new and exciting avenues in the study of the morphology of nanomaterials and biomaterials. Furthermore, studying the polarisation-dependent optical response of these materials could benefit the photonics community. More importantly, by binding SARS-CoV-2 with inorganic nanomaterials, which have a higher temperature stability than their organic counterparts, he has opened the possibility for the development of a vaccine that will not require refrigeration.

Written by Chirantan Mitra (PhD Student, Division of Physics and Applied Physics, SPMS NTU)

"The topic is very nice."- Ariyaldi (PhD Student, IGP)

"Informative presentation by the speaker and interesting questions brought up by the audience."- Ho Su Hian (PhD Student, MSE)

"The new knowledge about 3D chiral nanostructures."- Edbert Wing Hanitio (PhD Student, IGP-NEWRI)