Detecting Lead Using DNA

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Lead poisoning is the number one environmental hazard to American children. (1) Nearly 1 million children in the United States have enough lead in their blood to cause irreversible damage to their brains, nervous systems, kidneys, or reproductive organs. (2) At higher levels, lead poisoning can cause coma, convulsions, and death. Most of these children absorb lead into their blood from sources in and around their own homes: old paint and contaminated dust and soil. Current methods for detecting lead require sophisticated scientific equipment or complicated sample preparation.

Dr. Yi Lu and one of his students at the University of Illinois at Urbana-Champaign developed a simple, inexpensive method to detect and measure lead in the environment. (3) The technique harnesses DNA as a biosensor that literally glows in the dark when it contacts the metal. The scientists designed a specific strand of DNA that twists into a pocket tailor-made to capture lead. The method is extremely sensitive and can measure quantities of the metal over a wide range of concentrations.

Because DNA is stable and can easily be used in optical fibers and microchips, the technique might be used not only to detect household lead, but also on a larger scale to monitor lead in wastewater and industrial processes. The researchers also state that by varying the DNA and other chemicals, they can modify the technique to detect other metals, including those that are toxic, such as mercury and cadmium, and those that are beneficial to humans, such as calcium and potassium. Finally, the work will teach scientists more about the sequences and shapes of DNA that normally bind metals in the body. The researchers have applied for a patent on the work.


1 Fact Sheet #8: Lead 3/ 97. National Institute of Environmental Health Sciences.

2 Lead Fact Sheet. Centers for Disease Control and Prevention, 1998.

3 Li J, Lu Y. A highly sensitive and selective catalytic DNA biosensor for lead ions. J. Am. Chem. Soc. 122:10466-7, 2000.

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