Last updated October 25, 2018 at 1:18 pm
The innocent colourful blocks from your childhood could be part of our greatest tool in a nerve gas attack.

US Marine Corps soldiers participate in a training exercise. Credit: US Marine Corps and Sgt. Salvador R. Moreno
Nerve agents are scary stuff. And frighteningly, they have been used in public several times in the last year – the attempted assassination of Sergei Skripal, the killing of Kim Jong-nam in Malaysia, and in separate attacks on civilians in Khan Shaykhun and Douma in Syria a few examples.
They are among the deadliest substances on earth, yet can be odourless, tasteless and difficult to detect.
But now we have a new extremely powerful tool for investigating a nerve agent attack and it’s made out of the last thing you’d expect – Lego.
The innocent colourful clip-together blocks from your childhood, together with some extremely clever chemistry and your mobile phone, have been combined to build a brand new fast, cheap and easy device for detecting these poisons.
Responding to a nerve agent attack
One of the biggest challenges in the immediate aftermath of a nerve agent attack is detecting the compounds used so that the correct treatment can be used immediately.
Because nerve agents shut off enzymes that control the body’s nervous system function, death comes quickly — in minutes or even seconds.
However, current methods take too long and require expensive instruments that are poorly suited for field use.
Enter Lego.
Researchers from the University of Texas at Austin have used the blocks to build a simple inexpensive device that could be used in the field at nerve gas attack sites.
The simple design features a Lego box which has slots and guides to ensure that a user can quickly put together a sensitive detector. Into one slot the user puts their mobile phone to act as a camera, while other trays and attachment points position and secure a UV/visible lamp and a standard 96-well test plate inside the box. The clip-together ability of the Lego means that everything can slot into the correct position, while also being built cheaply and repaired easily.

Lego and a smartphone are components of a device that detects and quantifies nerve agents. Credit: American Chemical Society
However, while the Lego box allows easy use in the field, the real innovation comes in the chemistry of the system.
The researchers developed a cascade of reactions that amplify an optical signal that results from a decomposition reaction of the nerve agents. The resulting mixtures change their colour and intensity relative to the amount of chemical weapon present.
That visual change can then be read using simple equipment – in the field this can be the mobile phone with custom software for analysis.
The new chemical analysis also overcomes one big complication of other systems. There are two main categories of nerve agents, each of which requires a different decontamination protocol. Existing tools are not effective in differentiating between these classes, which is important because one is more toxic and less volatile than the other, leading to a greater potential for mass harm.
The researcher’s new system can discriminate between the nerve agent type, allowing more effective responses.
Between the low cost, modular and simple Lego box and the easily obtained equipment, the researchers hope that their new analytic method can be quickly adopted world wide and in conflict areas. To encourage this, the researchers uploaded their analytic code, image guides, and a demonstration video to GitHub.
The research has been published in ACS Central Science.