Team creates first-ever VX neurotoxin detector

City College of New York, associate professor of physics Ronald Koder and his team at the Koder Lab are advancing the field of molecular sensing by developing the first proteins that can detect a lethal nerve agent called VX in real time and without false positives from insecticides.

VX is classified as a neurotoxin and an incredibly deadly chemical warfare agent that has been used in assassinations by some countries. It can cause permanent brain damage in those who survive exposure.

These potentially life-saving findings are published in the July 2022 edition of: Scientific progress, with lab member Jim McCann who is the paper’s primary author. It outlines the design of two proteins that detect the neurotoxin by changing their shape in the presence of VX.

In collaboration with Douglas Pike and Vikas Nanda of Rutgers University, the CCNY team used a protein design program called ProtCAD to design 20 different proteins. According to Koder, the computer code was new and unlike anything the team had worked with before, so it came as a bit of a surprise that two of their protein designs worked quite quickly.

“The first thing we tried with a small molecule that actually just worked, it was pretty good,” Koder said. “In that absence of VX, all negative charges repel each other and then the protein unfolds. And it really stretches, almost like a stick. When the egg white binds VX it wraps all the way around the molecule and becomes much more compact.”

Previous detectors for this type of molecule were often produced false positives of chemicals such as insecticides. This new design can help avoid those misleading results by scanning the entire molecular surface to within a hundred millionth of a centimeter.

“We get this remarkable specificity because we’re making contact with the whole molecule,” Koder said.

This work contributes to a rapidly advancing field of biosensing technology used to detect the presence of incredibly small molecules called biomarkers.