Role of thin film refractive index contrast in the design and performance of nano-photonic crystal D-shaped fiber devices for label-free biosensing
Achieving a high figure of merit alongside exceptional sensitivity is critical for advancing optical biosensors capable of ultra-low limits of detection. In this work, we investigate the performance of D-shaped single-mode fiber devices coated with 1D photonic crystal stacks. These nano-assembled layers, composed of alternating high- and low-refractive-index (RI) materials, enable the excitation of Bloch surface waves (BSWs). By systematically varying the RI contrast between the layers, we demonstrate that while a moderate increase in RI contrast improves sensitivity and narrows the full width at half maximum (FWHM) of the BSW resonance, the sensitivity tends to stabilized as we further increase the RI contrast, while the FWHM still can be pushed towards a higher FoM. Real-world applicability is validated through the detection of immunoglobulin G (IgG) at record-low concentrations of 70 aM, leveraging the solution as a versatile, <i>operando</i>, high-performance biosensing platform.
Authors
- Monika Janik (ORCID: https://orcid.org/0000-0002-8002-3055)
- Dayron Armas (ORCID: https://orcid.org/0000-0003-1720-3165)
- Ignacio R. Matı́as (ORCID: https://orcid.org/0000-0002-2229-6178)
- Ignacio Del Villar (ORCID: https://orcid.org/0000-0002-8130-4035)
- Rukmani Singh (ORCID: https://orcid.org/0000-0002-7562-7217)
- Norbert Kwietniewski (ORCID: https://orcid.org/0000-0002-5672-9744)
- Esteban Gonzalez-Valencia
- Emil Pitula
- Francesco Chiavaioli (ORCID: https://orcid.org/0000-0002-3169-7395)
- Ambra Giannetti (ORCID: https://orcid.org/0000-0002-0002-2977)
- Mateusz Śmietana (ORCID: https://orcid.org/0000-0002-6774-2426)
- Dariusz Burnat (ORCID: https://orcid.org/0000-0003-0698-9211)
- Pedro Torres (ORCID: https://orcid.org/0000-0003-0544-6223)
- Shadab Dabagh (ORCID: https://orcid.org/0000-0002-5435-0597)
- Claudia Borr
Institutions
- Warsaw University of Technology (PL)
- Universidad Pública de Navarra (UPNA) (ES)
- Universidad Nacional de Colombia (CO)
- Nello Carrara Institute of Applied Physics (IT)
- Instituto Tecnológico Metropolitano (CO)
- National Research Council (IT)
Publication Details
- Published
- 2025-05-22
- DOI
- https://doi.org/10.1117/12.3060710
- Primary Topic
- Advanced Fiber Optic Sensors
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Grantová Agentura České Republiky
- Universidad Nacional de Colombia
- Politechnika Warszawska
- Universidad de Navarra
- Narodowym Centrum Nauki
- Universidad Pública de Navarra
- Instituto Tecnológico Metropolitano
- Agencia Estatal de Investigación