September 3, 2015
Researchers at UC Davis have made progress developing a technique to detect disease-causing agents in humans and plants.
In two recent papers in Analytical Chemistry (1 and 2), a group from the Department of Electrical and Computer Engineering demonstrated that they could detect nucleic acids (biomarkers of human and plant pathogens) using nanoporous gold, a novel sensor coating material. This method enables sensitive detection of DNA in complex biological samples, such as serum from whole blood.
“Nanoporous gold can be imagined as a porous metal sponge with pore sizes that are a thousand times smaller than the diameter of a human hair,” said Erkin Şeker, assistant professor of electrical and computer engineering at UC Davis and the senior author on the papers. “What happens is the debris in biological samples, such as proteins, is too large to go through those pores, but the fiber-like nucleic acids that we want to detect can actually fit through them. It’s almost like a natural sieve.”
Rapid and sensitive detection of nucleic acids plays a crucial role in early identification of pathogenic microbes and disease biomarkers. Current sensor approaches usually require nucleic acid purification that relies on multiple steps and specialized laboratory equipment, which limit the sensors’ use in the field. The researchers’ method reduces the need for purification.
“So now we hope to have largely eliminated the need for extensive sample clean-up, which makes the process conducive to use in the field,” he said.
The result is a faster and more efficient process that can be applied in many settings.
This technology is expected to translate into the development of miniature point-of-care diagnostic platforms for agricultural and clinical applications.
“The applications of the sensor are quite broad ranging from detection of plant pathogens to disease biomarkers,” said Şeker.
For example, in agriculture, scientists could detect whether a certain pathogen exists on a plant without seeing any symptoms. And in sepsis cases in humans, doctors could determine bacterial contamination much more quickly than they currently can, preventing any unnecessary treatments.
Other authors of the studies were Pallavi Daggumati, Zimple Matharu, and Ling Wang in the Department of Electrical and Computer Engineering at UC Davis.
This work is funded by the UC Davis grant Research Investments in the Sciences and Engineering (RISE), which encourages interdisciplinary work to solve problems facing the world today, as well as UC Lab Fees and National Science Foundation grants. Şeker is a co-lead on the RISE team investigating plant pathogen detection, dubbed RAPID-NEED.
On the homepage: Nanoporous gold, a novel sensor coating material, which the researchers have recently used for an advanced neural electrode as part of a collaboration with Lawrence Livermore National Laboratory and the UC Davis School of Veterinary Medicine.