SERS, nanoprobes seek to detect infections early

Ashley N. Rice, ashley.rice@photonics.com

Nanoprobes can be used with surface-enhanced Raman spectroscopy (SERS) to reveal a specific molecular marker’s optical fingerprint and to detect infections before patients even show symptoms, according to a recent study.

Biomedical engineers and genome researchers at Duke University developed the approach and have demonstrated it in human samples; they are now developing the technique for placement on a chip to provide simple patient information quickly.

“We have demonstrated for the first time that the use of these nanoprobes can detect specific genetic materials taken from human samples,” said Tuan Vo-Dinh, the R. Eugene and Susie E. Goodson Distinguished Professor of Biomedical Engineering in Duke’s Pratt School of Engineering and director of the university’s Fitzpatrick Institute for Photonics. His team collaborated with scientists at the university’s Institute for Genome Sciences & Policy (IGSP), who have developed a method of measuring the host’s response to infection through RNA profiling.

Tuan Vo-Dinh. Courtesy of Duke University.

The silver-based nanoparticle they developed targets a specific molecular marker that spills into the bloodstream at the first stages of an infection. When light is aimed at the sample, the nanoparticle attached to a molecular marker will reflect a distinct optical fingerprint.

“When the target molecule is coupled with a metal nanoparticle or nanostructure, the Raman response is greatly enhanced by the SERS effect – often by more than a million times,” said Vo-Dinh, who has been studying the potential applications of SERS for decades.

“This important proof-of-concept study now paves the way for the development of devices that measure multiple genome-derived markers that will assist with more accurate and rapid diagnosis of infectious disease at the point of care,” said Geoffrey Ginsburg, director of genomic medicine at the IGSP. “This would guide care decisions that will lead to more effective treatment and improved outcomes of antimicrobial therapy.”

The research appears online in Analytica Chimica Acta (doi: 10.1016/j.aca.2013.05.017).