Nanoshell Structures Could Form Basis of Future Biosensors

Scientists from four universities in the United States have created a way to use light-activated nanoshells as building blocks for 2-D and 3-D structures. They believe that the structures could eventually be used in biochemical sensors and other applications. The research appears in the journal Science.

"We used the method to make a seven-nanoshell structure that creates a particular type of interference pattern called a Fano resonance," explains Peter Nordlander, professor of physics and astronomy at Rice University (Houston). "These resonances arise from peculiar light wave interference effects, and they occur only in man-made materials. Because these heptamers are self-assembled, they are relatively easy to make, so this could have significant commercial implications."

Because the new materials can trap light, store energy, and bend light in bizarre ways that no natural material can, the new materials are suited for making ultrasensitive biological and chemical sensors, according to Nordlander.

Nanoshells, the building blocks that were used in the new study, are about 20 times smaller than red blood cells. By varying the size of the glass center and the thickness of the gold shell, nanoshells can be created that interact with specific wavelengths of light.

"Nanoshells were already among the most versatile of all plasmonic nanoparticles, and this new self-assembly method for complex 2-D and 3-D structures simply adds to that," remarks Naomi Halas, professor in electrical and computer engineering and professor of physics, chemistry, and biomedical engineering at Rice University. Haas has helped develop a number of biological applications for nanoshells, including diagnostic applications and a minimally invasive procedure for treating cancer.

More information on this research is available from PhysOrg.