Plasmonic Paper

Common filter paper decorated with gold nanoparticles used to create sensitive chemical/biological detection system — work described at the AVS meeting in Baltimore next month

Using a common laboratory filter paper decorated with gold nanoparticles, researchers at Washington University in St. Louis have created a unique platform, known as “plasmonic paper,” for detecting and characterizing even trace amounts of chemicals and biologically important molecules—from explosives, chemical warfare agents and environmental pollutants to disease markers.

The work will be described by Srikanth Singamaneni, assistant professor in the department of mechanical engineering and materials science at Washington University in St. Louis, and postdoc Limei Tian at the AVS 61th International Symposium and Exhibition, held Nov. 9-14, at the Baltimore Convention Center in Baltimore, Md.

Plasmonics involves the control of light at the nanoscale using surface plasmons, which are coordinated waves, or ripples, of electrons that exist on the surfaces of materials, and in particular metals such as gold. Localized surface plasmons of metal nanostructures result in unique optical properties with characteristics that depend upon the metal composition, size and shape of structures, the surrounding medium, and so on.

Tian and Singamaneni created their plasmonic paper by immersing common cellulosic filter paper into a solution of gold nanoparticles. Such a simple optically active platform can be employed to enhance the fingerprint signal of chemicals, revealing the identity of a trace amount of a compound such as a chemical warfare agent. In addition clinically important proteins can be captured by modified plasmonic paper and detected based on changes in the optical spectra that result when the proteins bind to the paper.

“In-field detection of chemical and biological threats is the challenge that we are trying to address,” Tian said. “This technology can be broadly used for chemical and biological sensing, including homeland security, forensics and environmental monitoring, and medical diagnostic applications.”

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