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Surface-Enhanced Infrared Absorption Using Individual Cross Antennas Tailored to Chemical Moieties

2013; American Chemical Society; Volume: 135; Issue: 9 Linguagem: Inglês

10.1021/ja312694g

1943-2984

Lisa V. Brown, Ke Zhao, Nicholas King, Heidar Sobhani, Peter Nordlander, Naomi J. Halas,

Advanced biosensing and bioanalysis techniques

The development of antenna structures for surface-enhanced infrared absorption spectroscopy (SEIRA) is a topic of intense and growing interest for extending IR spectroscopy to zeptomolar quantities and ultimately to the single-molecule level. Here we show that strong infrared spectroscopic enhancements can be obtained from individual gold nanoantennas using conventional IR spectrometric sources. The antenna structure dimensions can be tuned to enhance the IR modes of specific chemical moieties. Simulations of the electric field intensity in the antenna junction region reveal a maximum SEIRA enhancement factor of more than 12,000. These findings open new opportunities for analyzing IR vibrations of exceptionally small quantities of molecules using widely accessible light sources.