Moiré chiral metamaterials and their application on label-free enantiodiscrimination of drug molecules

Real-time analytical device enables continuous manufacturing of pharmaceutical ingredients


Pharmaceutical drugs are typically made in large batches with multi-step processes. A typical batch manufacturing facility contains multiple pieces of complicated equipment and can require an investment of billions of dollars. Batch manufacturing processes are not amenable to automation and cannot be easily scaled to meet changing production needs. On the other hand, continuous manufacturing processes are compatible with automation and production can be modified to meet demand.  For most pharmaceutical ingredients, continuous manufacturing would be significantly more cost effective to set up and operate than batch manufacturing.1

Despite the economic benefits, the pharmaceutical industry has been slow to adopt continuous manufacturing, likely due to the highly regulated nature of pharmaceutical ingredients and the potential hazards of impurities. As an example, R‑thalidomide is an effective painkiller; but its enantiomer, S‑thalidomide, can cause deformities in newborns. Current methods for detecting enantiomers include x-ray crystallography, high-performance liquid chromatography, and chiroptical spectroscopy. These methods are too slow to provide real-time feedback and require a large amount of sample for detection. New analytical tools are needed to use continuous manufacturing in the pharmaceutical industry.

The Zheng Research Group at UT Austin are experts at photonics and light responsive materials. Recently, they developed a photonic device with novel metamaterials that can discriminate enantiomers with picogram sensitivity.2 This new approach requires only a single drop of sample and can monitor chirality in real-time. This device can continuously monitor the chirality of biomolecules and drug molecules during production.

The generation of real-time process data makes continuous manufacturing possible and supports the FDA’s quality-by-design (QbD) approach of manufacturing.  The Zheng lab’s chiral sensing device has the potential to become an essential component in the multi-billion dollar market for continuous manufacturing of pharmaceuticals.


1.  Schaber, S. et al., Ind. Eng. Chem. Res. 2011, 50, 17, 10083–10092. Publication date: July 27, 2011

2.  Wu, Z., et al., Chiral Metamaterials via Moiré Stacking. Nanoscale 10 (2018) 18096-1811.