Simple and Inexpensive Paper-Based Assay for LeadEPA Grant Number: SU839890
Title: Simple and Inexpensive Paper-Based Assay for Lead
Investigators: Toote, Lauren E , Read-Daily, Brenda
Institution: Elizabethtown College
EPA Project Officer: Page, Angela
Project Period: October 1, 2019 through September 30, 2020
Project Amount: $23,811
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
There are 6.1 million lead water service lines in United States. This fact leaves many Americans in a precarious situation, as slight changes in the properties of their water, such as pH, could result in the leaching of lead into their tap water. Unfortunately, the average person does not have the ability to test for lead in their tap water. This problem exists because current technologies for lead detection are expensive and require trained personnel. As a result, these tests are performed in laboratory settings, not in homes. To address issue, we propose a simple and inexpensive paper test for lead (II) (Pb2+) in tap water. In this test, polymer nanoparticles, which encapsulate a molecular probe that has a colorimetric response to lead (II), will be anchored at the test line of a lateral flow assay. As a tap water sample flows down the strip, if lead (II) in present, a signal will result from the interaction of the lead (II) ions with the molecular probe. This signal can be visually observed by the user, giving communities which fall victim to contaminated water the opportunity to test their water and have control over their health.
A simple and inexpensive test for lead in tap water will be developed based on the concept of lateral flow. This assay design is used in pregnancy tests, so the general population is familiar with its format. Lateral flow assays display a positive signal by the appearance of a test line in the presence of an analyte of interest. In this proposal, the test line response will come from a phenanthroline-based probe that has a colorimetric response to lead (II). This probe will be incorporated into nanoparticles made from poly (acrylic acid), which will both increase its solubility in aqueous conditions as well as provide a scaffold for attachment of the probe to the lateral flow strip. Once these nanoparticles are anchored to the test line through hydrophobic interactions, a tap water sample can simply be added at the sample port and lateral flow will carry it down the strip. Assuming lead (II) is present, a color change will be observed from interaction of the probe, with lead (II), at the test line. This design will give agency to those affected by contaminated water through the ability to test their own tap water and determine whether or not it is safe. As they have this opportunity to participate in the improvement of their own health and environment they will become more educated about and invested in the importance of safe drinking water. Furthermore, this primarily paper-based test is inexpensive, especially relative to atomic spectroscopy instrumentation that is often used in lead analysis. As a result, this test will be a sustainable solution for monitoring the quality of tap water, providing continued prosperity to affected populations. Finally, the interdisciplinary team formed to execute this research will provide an environment for students from different departments to learn from each other about how the P3 approach is integrated into each part of the project. This work will also be presented at campus-wide research events and incorporated as a real-life example in both analytical chemistry and environmental engineering courses.
Molecular probes have been shown to be effective in detection of heavy metals and lateral flow assays have been implemented throughout the world as diagnostics that can be used by the general public. Through the combination of these two techniques we expect to produce a simple and inexpensive test for lead in drinking water. We foresee this test providing a visual signal, that can be interpreted by an untrained user, for samples containing ppb levels of lead. In Phase 1 of this grant, results will be evaluated through comparison of the test response to that of atomic emission spectroscopy, a common laboratory method.