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There is growing concern around the negative health impacts associated with contamination of drinking water by harmful chemicals. Technology that enables fast, cheap, and easy detection of ions and small molecules in drinking water is thus important for reducing the incidence of these negative health impacts. Here, we describe a sensor for detecting Cu2+ in water that provides colorimetric results in fifteen minutes or less and functions in a just-add-water format. The sensor contains cheap reagents including salts, buffer, oxidant, chromogen, surfactant, and optionally a chelating agent. The sensor is assembled and lyophilized for shelf-stability and field-deployment. Rehydrating the sensor with water containing Cu2+ results in chromogen oxidation and blue color formation to visually indicate the presence of Cu2+. The sensor demonstrates high selectivity toward Cu2+ against other metal ions, functionality in field samples, shelf-stability, and can be tuned to activate at different Cu2+ threshold concentrations. This sensor thus has the potential to meet a variety of needs, such as point-of-need testing for Cu2+ to ensure water supplies meet health guidelines, such as the United States Environmental Protection Agency’s Lead and Copper Rule. 

Perceptions of drinking water safety shape numerous health-related behaviors and attitudes, including water use and valuation, but they are not typically measured. We therefore characterize self-reported anticipated harm from drinking water in 141 countries using nationally representative survey data from the World Risk Poll (n=148,585 individuals) and identify national- and individual-level predictors. We find that more than half (52.3%) of adults across sampled countries anticipate serious harm from drinking water in the next two years. The prevalence of self-reported anticipated harm is higher among women (relative to men), urban (relative to rural) residents, individuals with self-reported financial difficulties (relative to those getting by on their present income), and individuals with more years of education. In a country-level multivariable model, the percentage of the population reporting recent harm from drinking water, percentage of deaths attributable to unsafe water, and perceptions of public-sector corruption are associated with the prevalence of self-reported anticipated harm. Consideration of users’ perspectives, particularly with respect to trust in the safety and governance of water services, is critical for promoting effective water resource management and ensuring the use, safety, and sustainability of water services. 

Industrialization and failing infrastructure have led to a growing number of irreversible health conditions resulting from chronic lead exposure. While state-of- the-art analytical chemistry methods provide accurate and sensitive detection of lead, they are too slow, expensive, and centralized to be accessible to many. Cell-free biosensors based on allosteric transcription factors (aTFs) can address the need for accessible, on-demand lead detection at the point of use. However, known aTFs, such as PbrR, are unable to detect lead at concentrations regulated by the Environmental Protection Agency (24−72 nM). Here, we develop a rapid cell-free platform for engineering aTF biosensors with improved sensitivity, selectivity, and dynamic range characteristics. We apply this platform to engineer PbrR mutants for a shift in limit of detection from 10 μM to 50 nM lead and demonstrate use of PbrR as a cell-free biosensor. We envision that our workflow could be applied to engineer any aTF. 

ABSTRACT Deficiencies in knowledge about water quality prevent or obscure progress on a panoply of public health problems globally. Specifically, such lack of information frustrates effective and efficient government regulation to protect the public from contaminated drinking water. In this Practical Paper, we lay out how recent scientific innovations in synthetic biology mean that rapid, at-home tests based on biosensor technology could be used to improve water quality monitoring and regulation, using the example of the U.S. Environmental Protection Agency's Lead and Copper Rule currently under revision. Biosensor tests can be used by non-scientists and the information that biosensor tests generate is relatively cheaper and faster than standard laboratory techniques. As such, they have the potential to make it possible to increase the number and frequency of samples tested. This, in turn, could facilitate more accurate compliance monitoring, justify more protective substantive standards, and more efficiently identify infrastructure priorities. Biosensors can also empower historically underrepresented communities by facilitating the visibility of inequities in lead exposure, help utilities to ensure safe water delivery, and guide policy for identifying and replacing lead-bearing water infrastructure, thereby improving public health. As the technology matures, biosensors have great potential to reveal water quality issues, thereby reducing public health burdens. 

Synthetic biology allows us to reuse, repurpose, and reconfigure biological systems to address society’s most pressing challenges. Developing biotechnologies in this way requires integrating concepts across disciplines, posing challenges to educating students with diverse expertise. We created a framework for synthetic biology training that deconstructs biotechnologies across scales—molecular, circuit/network, cell/cell-free systems, biological communities, and societal—giving students a holistic toolkit to integrate cross-disciplinary concepts towards responsible innovation of successful biotechnologies. We present this framework, lessons learned, and inclusive teaching materials to allow its adaption to train the next generation of synthetic biologists.