PROJECT SUMMARY/ABSTRACT Safe drinking water is essential for public health yet is increasingly threatened by anthropogenic activities and aging infrastructure that contaminate it with heavy metals and other toxins. Most notable in the United States is the contamination of drinking water with lead, a heavy metal that is pervasive in America’s water infrastructure and indoor plumbing. Chronic exposure to lead results in numerous adverse health and societal outcomes and is an environmental injustice that widens inequalities. Upon discovery, lead contamination can be mitigated by changing drinking water source, flushing, and existing filtration technologies. However, as recent events such as the crises in Flint, MI or Newark, NJ exemplify, improper management can lead to major public health threats by creating community-wide exposure to dangerously high levels of lead. Lead contamination of drinking water is widespread across the United States due to aged infrastructure and domestic plumbing that heavily relied on lead. Frequent monitoring for the presence of lead contamination in drinking water is part of the solution. It can identify where problems exist, alert consumers without delay, and inform risk mitigation and remediation strategies. However, reliable testing remains limited to analytical chemistry techniques that are costly, time consuming, and require substantial laboratory infrastructure and technical expertise. This complicates the large- scale of testing needed to address the lead in drinking water crisis and is a barrier to the routine testing of water supplies by consumers. Here, we propose to address these issues by pursuing the next stage of development of our technology platform that will allow for the reliable, inexpensive, on-site, and on-demand monitoring of lead in drinking water. Our technology is built from recent innovations in synthetic biology that allow us to repurpose biological sensor proteins that detect specific toxic ligands, such as heavy metals, into ‘cell-free’ reactions that produce detectable signals when lead is present. These biochemical reactions are safe and can be embedded on paper devices for long term storage and distribution. Adding water to these paper-based devices activates the biochemical reaction and produces a visual signal in the presence of a toxic compound. This Phase II proposal details a series of complementary aims for achieving improved specificity and sensitivity of this lead testing device, using a human-centered design process to improve test operation and results interpretation, and adapting our manufacturing and quality assurance/quality control processes for a scale-up of manufacturing capability for validation studies. A successful outcome of this proposal will lead to a rapid lead test with sensitivity comparable to laboratory testing, an accessible and easy-to-use device format with a companion mobile app, and pilot-scale production to validate our lead sensing technology in the laboratory and in the field. This work will enable manufacturing and commercial distribution of a highly sensitive and rapid lead biosensor, which will help address the growing water quality crisis in the United States and beyond.

PROJECT NARRATIVE Clean drinking water—free of contaminants such as the heavy metal lead—is essential to public health, as chronic consumption of lead, even at low levels, can lead to myriad health issues including developmental and physical disabilities. Currently, the only reliable methods of detecting lead contaminants in water do not scale as they involve the off-site collection, preservation, and transportation of water samples to analytical chemistry laboratories, can cost upwards of hundreds of dollars, and take weeks to provide results on the safety of a single water sample. We propose to develop an inexpensive and easy-to-use device for the on-site, on- demand detection of lead in water to identify lead hazards in drinking water and ultimately reduce exposure to water contaminants.