February 21, 2016

UNL researcher finds gold -- and other metals

The photo at left shows the gold biosensor developed by Rebecca Lai, associate professor of
chemistry at the University of Nebraska. The DNA probe is immobilized on a gold electrode
contained within the circle. A water sample, as small as 10 microliters, is applied to the sensor
through the center of the crystal cube. The white, green and red leads attached to the contact
pads connect to a handheld power source. The center diagram illustrates how gold ions
connect two strands of adenine and hinder electron

(February 21, 2016)  Instead of a pan and a pick ax, prospectors of the future might seek gold with a hand-held biosensor that uses a component of DNA to detect traces of the element in water.

The gold sensor is the latest in a series of metal-detecting biosensors under development by Rebecca Lai, an associate professor of chemistry at the University of Nebraska-Lincoln. Other sensors at various stages of development detect mercury, silver or platinum. Similar technology could be used to find cadmium, lead, arsenic, or other metals and metalloids.

A primary purpose for the sensors would be to detect water contaminants, Lai said. She cited the August 2015 blowout of a gold mine near Silverton, Colorado, which spilled chemicals into nearby rivers, as well as the ongoing problems with lead-tainted water supplies in Flint, Michigan.

Rebecca Lai

Fabricated on paper strips about the size of a litmus strip, Lai's sensors are designed to be inexpensive, portable and reusable. Instead of sending water samples away for time-consuming tests, people might someday use the biosensors to routinely monitor household water supplies for lead, mercury, arsenic or other dangerous contaminants.

But Lai also is among scientists searching for new and better ways to find gold. Not only aesthetically appealing and financially valuable, the precious metal is in growing demand for pharmaceutical and scientific purposes, including anti-cancer agents and drugs fighting tuberculosis and rheumatoid arthritis.

read entire press  release >>