Laser Fragment Counting Offers New Route to Chiral Molecule Identification

Researchers have developed a method that uses twisted laser light to distinguish mirror-image molecules by counting ion fragments, potentially simplifying pharmaceutical analysis.

This article was drafted with AI assistance from multiple sources and was reviewed and approved by a human editor before publication.

A team of scientists has demonstrated a new way to tell apart mirror-image molecules, known as enantiomers, by counting the fragments they produce when struck by specially shaped laser pulses. The work, published in Science Advances on July 26, 2026, could offer a simpler alternative for chiral analysis in drug development.

The study was conducted by researchers at the Tata Institute of Fundamental Research (TIFR), the Indian Institute of Technology Bombay, and the Indian Institute of Technology Hyderabad. Experiments took place at the TIFR Hyderabad laser facility, where the team directed ultrashort laser pulses—lasting a few hundred femtoseconds—with controlled spin and twist at gaseous samples of either R-camphor or S-camphor.

When the twisted light interacted with the molecules, they broke apart into charged fragments. A time-of-flight mass spectrometer then analyzed these fragments. The key observation was that the number of fragments varied based on how the light's twist aligned with the molecule's handedness. This allowed the researchers to read chirality directly from the ion signal counts, bypassing the need for angular measurements or coincidence detection.

Because the technique works on molecules in the gas phase, it isolates them from solvents or surfaces, providing a clean environment for analysis. The use of structured light enhances the interaction, yielding more pronounced differences between enantiomers than conventional optical methods. The findings are detailed under DOI 10.1126/sciadv.aec6549, with Haritha Venugopal as the lead author among the research team.