Polarization modulated spectroscopic ellipsometry-based surface plasmon resonance biosensor for E. coli K12 detection

authored by: Soraya Zangenehzadeh, Emil Agocs, Fenja Schröder, Nassima Amroun, Rebekka Biedendieck, Dieter Jahn, Axel Günther, Lei Zheng, Bernhard Roth, Hans Hermann Johannes, Wolfgang Kowalsky
Abstract: In this work, we report on the application of the polarization modulated spectroscopic ellipsometry-based surface plasmon resonance method for sensitive detection of microorganisms in Kretschmann configuration. So far, rotating analyzer and single wavelength polarization modulation methods have widely been investigated for phase sensitive surface plasmon resonance measurement. In this study, a much simpler optical setup relying on fast electro-optic phase modulator crystals is introduced for bacteria detection. A beta barium borate crystal connected to a function generator is adapted for generating phase shifts in the millisecond regime to extract the ellipsometric angles (Ψ and Δ) under the surface plasmon resonance condition. For detection, the gold surface was functionalized with anti-Escherichia coli antibodies, and E. coli K12 was attached to them. We show that polarization modulated spectroscopic ellipsometry achieves a refractive index resolution in the order of 10^-5 RIU, and a limit of detection of 10² CFU/mL for E. coli K12 which is compatible with other surface plasmon resonance based phase sensitive methods with more complex detection concepts. As a follow-up step, an optical model can be developed to enhance this biosensor’s performance, and applications for sorting and detecting other biological targets will be investigated.
Organisation(s): PhoenixD: Photonics, Optics, and Engineering - Innovation Across Disciplines
Hannover Centre for Optical Technologies (HOT)
External Organisation(s): Technische Universität Braunschweig
Type: Article
Journal: Scientific reports
Volume: 14
No. of pages: 11
ISSN: 2045-2322
Publication date: 07.11.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General
Electronic version(s): https://doi.org/10.1038/s41598-024-78535-8 (Access: Open)