A Drinking Water Sensor for Lead and Other Heavy Metals

Leakage of lead and other heavy metals into drinking water is a significant health risk to humans and a major concern in the United States. Heavy metal leakage often occurs without the awareness of the users, as lead can be colorless and odorless. Early detection of lead is important to prevent long-term exposure but is difficult to achieve using current technology. Because water is contaminated inside the structure of a house, end-point detection by home-monitoring is crucial for lead leakage detection.

We have developed sensors consisting of platinum electrodes for the detection of heavy metal that have a long lifetime, cost around 10 cents per unit, and can be easily inserted in pipes for continuous monitoring. The sensors operate by measuring the impedance change between the electrodes. Two designs were created: A two-electrode sensor that can identify the existence of a variety of heavy metals, and a four-electrode sensor that can distinguish lead from other heavy metals. No false-positive response was generated when the sensors were placed in simulated and actual tap water contaminated by heavy metals. Lead detection on the four-electrode sensor was not affected by the presence of other common ions in tap water.