Detection of Heavy Metals by Colorimetric Nanoparticles

Poster Presentations

In the United States there are 6.1 million lead water service lines. This fact leaves many Americans in a precarious situation, as slight changes in the properties of their water supply (ex. pH), could result in the leaching of lead into their drinking water. Unfortunately, the average person does not have the ability to test for lead in water. This problem exists because current technologies for lead detection are expensive and require trained personnel. To address this issue, we propose a simple and inexpensive paper test for lead(II) in drinking water. This test will utilize polymer nanoparticles, which encapsulate a molecular probe that has a colorimetric response to lead(II), to produce a signal that can be visually observed by the user. In this work, a phenanthroline-based probe is synthesized and its colorimetric response to lead(II) assessed by UV-Vis spectroscopy. The probe is then incorporated into a polymer nanoparticle for increased stability in aqueous environments. Additionally, to ensure the test is reliable, a control is incorporated to confirm the test is working properly. To this end, polymer nanoparticles that encapsulate bromocresol green, a pH responsive dye, are also synthesized. These nanoparticles will produce a colorimetric signal when exposed to the pH of drinking water. Future work will look to incorporate these two nanoparticle systems into a paper lateral flow assay for simple and sensitive detection of lead(II).