Towards enhanced optical sensor performance: SEIRA and SERS with plasmonic nanostars

O Bibikova; J Haas; A I López-Lorente; A Popov; M Kinnunen; I Meglinski; B Mizaikoff

doi:10.1039/c6an02596j

Towards enhanced optical sensor performance: SEIRA and SERS with plasmonic nanostars

Analyst. 2017 Mar 13;142(6):951-958. doi: 10.1039/c6an02596j.

Authors

O Bibikova¹, J Haas², A I López-Lorente², A Popov³, M Kinnunen⁴, I Meglinski³, B Mizaikoff²

Affiliations

¹ Optoelectronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu 90570, Finland and Institute of Analytical and Bioanalytical Chemistry, Ulm University, 89081 Ulm, Germany. boris.mizaikoff@uni-um.de and Art Photonics GmbH, 12489 Berlin, Germany and Research-Educational Institute of Optics and Biophotonics, Saratov National Research State University, Saratov 410012, Russian Federation.
² Institute of Analytical and Bioanalytical Chemistry, Ulm University, 89081 Ulm, Germany. boris.mizaikoff@uni-um.de.
³ Optoelectronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu 90570, Finland and Interdisciplinary Laboratory of Biophotonics, Tomsk National Research State University, Tomsk 634050, Russian Federation and Terahertz Biomedicine Laboratory, ITMO University, St Petersburg 197101, Russian Federation.
⁴ Optoelectronics and Measurement Techniques Research Unit, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu 90570, Finland.

PMID: 28229133
DOI: 10.1039/c6an02596j

Abstract

We report the preparation and characterization of plasmonic chip-based systems comprising self-assembled gold nanostars at silicon substrates that enable concomitantly enhanced Raman (surface enhanced Raman spectroscopy; SERS) and mid-infrared (surface enhanced infrared reflection or absorption spectroscopy; SEIRA) spectral signatures. The high-aspect-ratio structure of gold nanostars provides an increased number of hot spots at their surface, which results in an electric field enhancement around the nanomaterial. Gold nanostars were immobilized at a silicon substrate via a thin gold layer, and α-ω-dimercapto polyethylene glycol (SH-PEG-SH) linkers. The Raman and IR spectra of crystal violet (CV) revealed a noticeable enhancement of the analyte vibrational signal intensity in SERS and SEIRA studies resulting from the presence of the nanostars. Enhancement factors of 2.5 × 10³ and 2.3 × 10³ were calculated in SERS considering the CV bands at 1374.9 cm^-1 and 1181 cm^-1, respectively; for SEIRA, an enhancement factor of 5.36 was achieved considering the CV band at 1585 cm^-1.