It all started with a local tv program, where AMOLF researcher Wim Noorduin first heard of the dangers of lead exposure. From a study by UNICEF and Pure Earth—an NGO focused on lead poisoning—he learned that the problem of lead exposure is very large: one in three children worldwide suffers from lead poisoning from paint, piping, informal recycling of batteries and many other sources, affecting among other things their brain development.
At AMOLF, Wim and his colleague Lukas Helmbrecht had been working on the conversion of various compounds into lead-containing semiconductors. Linking his research with the problems addressed in the tv program, Wim took some of the reagents home to see if they would react with lead pipes in his house. If so, these would light up bright green under UV light. Disappointingly, in his home nothing lit up, but the lead roof cladding of the neighbors did and - to his surprise the window sills also did. It turned out these contained lead paint. "They continued to shine for weeks!" recalls Wim.
The researchers realized they were on to something: an easy method to detect lead with a spray and a UV lamp. It could be used by anyone, including people living in countries in the Southern hemisphere, who are at much higher risk of lead poisoning than we are in the Northern hemisphere, explains Lukas: "My drive has always been to empower people to test their environment themselves, so they can take action to avoid lead poisoning."

Scale-up
Lukas developed the chemistry, hijacking the technology from their semiconductor research. First, the test kit went up for sale on the Lumetallix website and the researchers provided kits to scientists to do their own research. Then, the challenge was to find a way to scale up, says Wim. Only then can they reach their goals to raise awareness for the dangers of lead poisoning and to empower a large number of people to change their environment.
Getting in contact with Pure Earth and the Dutch environmental consultancy company Tauw, proved essential. Pure Earth set up a mission to India to try out different lead tests including the Lumetallix kit and Lukas joined. "India has one of the largest populations of children with lead poisoning. Every second child is affected," says Lukas. The test worked perfectly in the less-than perfect conditions of a monsoon-infested, polluted, wet, hot and bright climate. Previously, Pure Earth relied on expensive XRF measurements, which limits the number of tests that can be done.
The success resulted in a formal global collaboration with Pure Earth, which was signed in July. Lumetallix makes the kit available to their worldwide network and donates a portion of the proceeds to their mission. "NGO's have a very limited budget," explains Wim. "Only with this money that we contribute to them, can they scale up the roll-out of the lead detection kits and reach as many people as possible. For Lumetallix, scale is essential too."
"The circle is round," Wim reflects. "The idea of developing a lead test started with the tv program and the UNICEF and Pure Earth report, showing how many children are affected. Now these NGO’s are rolling out our test exactly for those children."

Crime scene investigation
Remarkably, the researchers recently published a very different application for their test: in forensics. Wim explains: "We identified this as a potential interest from the beginning, but we were not sure how. Until we got in contact with Arian van Asten." Working with Van Asten, a professor of forensic analytical chemistry at the University of Amsterdam (UvA), his masters student Kendra Adelberg and researchers from the Netherlands Forensic Institute NFI and the forensic police, they investigated the possibilities to detect lead from gunshots.
Firing a bullet from a gun releases a fine lead powder from the explosive charge. Detecting the lead dust and especially the deposition pattern provides a lot of information about the shooting, explains Wim. "It can tell the police if the gun was fired from close by or from far away and from which direction. The pattern contains information on the rifling of the gun - the spiral grooves in the barrel. And the coolest thing: it can detect lead particles on the hands of anyone who fired the gun, even after they have washed their hands."
Lukas set out to adapt the lead test to fit the protocol that forensic researchers use at crime scenes. The researchers then got rare access to a firing range to try out the new test. "It was exciting, suddenly we moved from finding lead in household environments to being subjected to security and background checks," smiles Wim.

Fast and sensitive
The results of the experiment were encouraging. Lead dust patterns are perfectly transferred to other surfaces, such as the structure of the original substrate, the shockwave pattern and the rifling pattern. The test is very sensitive because the lead particles are very small. "The smaller the better for our test, whereas in traditional analysis very small particles are a problem," according to Wim.
The forensic police is excited about the results, he says. "Our test is fast and sensitive and can be used to quickly get information after a shooting incident. The traditional analysis will still be done to confirm, for example, that a person has actually shot, instead of just touched lead from another source. But this analysis is expensive and can take hours to days to get the results. It can even be too late to use in a court case."
The research will be continued at UvA and AMOLF, on the forensic part to establish the sensitivity and limitations and on the scientific part to find reaction mechanisms and detection limits.
Fundamental research, such as at AMOLF may lead to an unexpected application. This is important to talk about, says Wim: "We often have to explain why we do this fundamental research. It's a valid question but this story shows that it is very important to do blue sky research. We never thought of all these applications when we started. I really appreciate how AMOLF has supported us throughout this process."