Grantee Research Project Results

Development of a Simple Enzyme Inhibition Biosensor for Lead in Drinking Water

EPA Grant Number: SU841134
Title: Development of a Simple Enzyme Inhibition Biosensor for Lead in Drinking Water
Investigators: Berberich, Jason , Boock, Jason , Danielson, Neil
Institution: Miami
EPA Project Officer: Callan, Richard
Phase: I
Project Period: March 1, 2025 through April 30, 2025
Project Amount: $75,000
RFA: 21st Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity, and the Planet Phase I (2024) RFA Text
Research Category: Health Effects , Urban Air Toxics , Endocrine Disruptors , Heavy Metal Contamination of Soil/Water , Drinking Water , Clean Water , Water Quality , Human Health , Water , P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources , Environment , Water Treatment

Description:

Our design will have a significant impact on people by indicating the presence of lead in drinking water, which has been shown to damage the central and peripheral nervous systems and cause learning disabilities, especially in young children, infants and fetuses.  Reducing lead exposure will improve people’s health, resulting in improved learning outcomes and building prosperity within their communities.  We expect a low-cost sensor to guide the replacement of plumbing fixtures such as lead service lines, which is an expensive repair.  Lead exposure through drinking water disproportionately affects low-income, minorities in both the United States and across the planet.  The implementation of simple, biodegradable paper-based lead test strips will have minimal waste and will reduce the release of lead into the environment to promote a clean planet. Students from the departments of Chemical, Paper and Biomedical Engineering and Chemistry and Biochemistry will work to complete this project. To be successful, undergraduate and graduate students will need to apply their diverse science and engineering backgrounds to construct a robust and precise test strip.  Students will learn to design, build, and test simple enzymatic biosensors for lead, resulting in a rapid, point-of-us diagnostic for lead contamination in drinking water in impacted communities. Student teams will need to consider a range of economic and environmental inputs to ensure the device’s long-term viability and widespread distribution. Students will disseminate findings by presenting their work at national, regional, and internal Miami conferences.  To expand the influence of this project, aspects of the sensor design and outcomes will be added to undergraduate course work as real-life examples of how engineering technology impacts human life.

Objective:

Consumption of lead through drinking water can have devastating effects on the human body.  Lead poisoning is especially of concern for young children where exposure can result in developmental delay and learning difficulties.  As an adult, exposure to lead may cause high blood pressure, headaches and difficulties with memory.  The most common source of lead exposure is through drinking water.  Pipes and other plumbing fixtures in the home may contain lead, lead alloys or lead-containing solder.  Exposure to oxygen or oxidizing disinfectants may cause corrosion of lead pipe surfaces, leaching it into drinking water.  Aging water distribution systems, the switching of water supplies and changes in water treatment procedures all increase the chance of lead contamination in drinking water supplies.  Additionally, due to the plumbing fixtures present, some homes may experience greater lead contamination than others, requiring assessment in each location. To help mitigate the risk of exposure to lead, we propose to design a simple, single-use test strip to be used by the general public to test drinking water at the faucet where the risk of lead exposure is highest. Our device represents a transformative technology that could significantly reduce exposure to lead for those who live in older homes where lead plumbing fixtures and service lines have not yet been replaced. Currently, there are very few reliable at-home test methods to rapidly test for lead at the drinking faucet, particularly at low levels near 15 ppb (µg/L) needed to meet the EPA standards for clean water.  Water samples are usually collected and shipped to a lab where complex instrumentation involving atomic spectroscopy or anodic stripping voltammetry is used to quantify lead. Our proposed test strip will be an enzymatic biosensor, similar to what is used for diabetic glucose monitoring. We intend to use the enzyme porphobilinogen synthase (PBGS), which is utilized as a biomarker for lead exposure and has been reported to be inhibited by lead at picomolar quantities. We expect that inhibition at such a low lead concentration to be key to designing a test strip sensitive enough for safe water assessment.  We plan to couple the enzyme reaction chemistries with a colorimetric indicator to indicate the presence of lead by a simple color change, easily readable at home. The proposed sensor will be low cost and disposable, filling the need for lead detection at home drinking water faucets.

Expected Results:

Our expected outcomes are: 1) identify, produce and purify a family of PBGS variants, 2) characterize the inhibition by lead, activity and stability of the PBGS mutants, 3) develop colorimetric chemistry for signal transduction, 4) develop and test a simple prototype device, and 5) characterize the impact of common chemical contaminants found in drinking water on the prototype sensor response.

Supplemental Keywords:

Lead, heavy metal, biosensor, enzymatic sensor, enzyme inhibition, environmental monitoring, drinking water, sustainable technology.

Progress and Final Reports:

Final