How Russian nerve agent Novichok can be detected after poisoning

On September 2, German Chancellor Angela Merkel revealed that Alexei Navalny, a Russian opposition politician and former journalist, had been poisoned with Novichok, a nerve agent—one of the infamous exotic Soviet-era chemical weapons, says Science Magazine in an article. Alexei Navalny’s supporters have accused Russian agents of slipping poison into the tea that he consumed.

Chancellor Merkel, did not reveal the tests that were conducted in a military lab, but scientists familiar with the nerve agent, however, they have an idea as to how the nerve agent was uncovered.

Like many nerve agents, Novichoks bind to acetylcholinesterase (AChE), an enzyme that breaks down the acetylcholine, a neurotransmitter. AChE harms the human body and can be fatal when released into synapses. Some common symptoms of Novichok poisoning include nausea, breathing difficulties, and seizures.

Without medical intervention, victims can lapse into a coma. Red blood cells have AChE anchored to their membranes, so a blood sample could yield a conjugate formed when a Novichok latches onto AChE, which scientists could detect using mass spectrometry, says Palmer Taylor, a pharmacologist at the University of California, San Diego (UCSD).

Another event that could happen is Novichok joining with serum albumin, which is the most abundant protein in blood. When this happens, there are “very useful markers” that can be detected in blood for at least two weeks after the poisoning, Stefano Costanzi, a chemist and nonproliferation analyst at American University in Washington, DC, told the website.

Alexei Navalny fell ill on August 20 after drinking a cup of tea at an airport in Siberia. He went into a coma and was flown to Germany's capital Berlin two days later. The German hospital treating him said in a statement that he is out a medically induced coma and is responding to stimuli.

A third possible combination is Novichok and butyrylcholinesterase (BChE), an enzyme that searches and consumes nerve agent molecules in blood. A straightforward approach would be to use an anti-BChE antibody to latch onto the combination and then digest the protein. Most of the Novichok molecule would remain linked to one of the fragments and would be easy to detect by mass spectrometry, Oksana Lockridge, a toxicologist at the University of Nebraska Medical Center told the publication.

Former Russian spy, Sergei Skripal was poisoned using Novichok too, in Salisbury, United Kingdom, in March 2018. In this incident, two Russian intelligence officers left a trail of evidence in the attempted assassination of Skripal. His daughter Yulia also fell ill after exposure to Novichok A234. Both of them survived the assassination attempt.

The attempt in Salisbury brought Novichoks back into public discourse. A Russian chemist in 1992 gave away some details about toxic Russian nerve agents of which there are at least seven of them, the US government and its allies restricted open discussion of the nerve agent. The brazen use of Novichok in the United Kingdom led to public outcry.