Scientists at Northwestern University collaborated to develop an accurate, inexpensive, and easy-to-use test for detecting toxic fluoride levels in water. A new biosensor developed at Northwestern was field-tested in rural Kenya, providing evidence that water testing for fluoride levels can be easily used outside of the laboratory and interpreted accurately by laypersons.

It is estimated that tens of millions of people around the world live in areas where their water is contaminated with toxic levels of natural fluoride, a colorless, odorless and tasteless substance. The extent of the problem has been difficult to quantify due to the high cost or complexity of the testing options available. A proven new testing method is an important step towards solving the global health challenge of access to safe drinking water and is the result of a rare collaboration between researchers in the fields of anthropology and synthetic biology.

The research was jointly led by Northwest anthropologist Sera Young and synthetic biologist Julius Lax. Young is an associate professor in the Department of Anthropology and Global Health Studies at the Weinberg College of Arts and Sciences and a researcher at the Policy Research Institute (IPR). Lax is professor and associate professor of chemical and biological engineering at the McCormick School of Engineering. Lax is also co-director of the Northwestern Center for Synthetic Biology, of which Young is a faculty member.

Yang and Lax say this is the first time they’ve brought together field data, and it shows what’s possible when sociologists and synthetic biologists put their heads together to solve global problems. The project builds on previous research conducted by married Lax and Young and finds a unique intersection.

In 2017, Yang and colleagues developed a water safety rating scale to provide a global measure of water safety that takes into account human experience. Young is working with the Gallup World Poll to publish forecasts for half the world on the WISE scale by 2022 in the Lancet Planetary Health.

Powered by Young’s research, Lax and his lab began investigating natural biosensors, the molecules microbes use to detect the presence of pollutants. In 2020, they published a paper on reusing biosensors in a cell-free synthetic biological system to detect harmful water pollutants such as fluoride in the field, naming their technology platform ROSALIND.

To continue Young’s research to improve global water security, the latest iteration of Lucks Lab’s ROSALIND technology has improved the device’s speed and usability, allowing the device to easily transport harmful levels of fluoride to areas where it poses a safety concern.

The research team collected 57 water samples from 36 rural households in Kenya to evaluate the accuracy of fluoride concentration measurements compared to the gold standard fluoride photometer method. They also designed their research to see if test results could be easily interpreted by non-expert users; This is an important indication that technology can have a significant impact in resolving the global water crisis.

The results were remarkable, showing that the point of use had an 84% chance of correctly estimating fluoride levels above the World Health Organization’s 1.5 ppm limit. The tests were also very user-friendly, with only 1 out of 57 tests having interpretation differences between the user and the science team.

“This is a completely new way of measuring water quality,” said Young. “The research shows that we can put in the hands of people a test that relies on very complex biology but works very simply.”

“It also demonstrates the feasibility of this type of testing for other chemicals like lead and PFAS,” Lax said.

Possible next steps for point-of-use fluoride testing may include mapping the worldwide locations of geogenic fluoride. Closer to their Chicago home, Young and Lacks are interested in investigating the feasibility of using a home test to quickly detect lead in water and using this research as a model for the interaction of social science and synthetic biology to increase the impact of synthetic biology. biology innovation.