Authors: C.J. Choi, S. Semancik
Affilation: National Institute of Standards and Technology, United States
Pages: 28 - 31
Keywords: optical sensor, plasmonic nanodome array, replica molding, surface plasmon resonance, surface-enhanced Raman scattering
Label-free optical sensors have recently emerged as a highly sensitive approach for detecting a broad range of chemical and biological analytes that include illicit drug compounds, explosives, proteins, viruses, and bacteria.To best meet such diverse monitoring needs, different sensing methods have been used. For example, detection of chemical compounds typically requires specific chemical identification method, such as Raman spectroscopy, while proteins or bacteria are most effectively detected by performing capture affinity assays using surface plasmon resonance biosensors. Therefore, the integration of multiple detection modalities into a single, substrate-based sensing platform would offer highly complementary capabilities that allow a variety of analytes to be detected simultaneously. This work describes a label-free, optical sensor system fabricated on a flexible plastic film using nanoreplica molding process with dual detection modalities: surface-enhanced Raman scattering (SERS) for specific chemical identification and localized surface plasmon resonance (LSPR) for capture affinity biosensing. The sensor surface is comprised of a close-packed array of 383 nm diameter dome structures with interdome spacing of 14 nm, fabricated by a process that combines nanoreplica molding and unpatterned blanket deposition of SiO2 and Ag thin films.