Metasurface‐Enhanced Lab‐on‐Fiber Biosensors. Issue 12 (6th September 2020)

• Record Type: Journal Article
• Authors: Consales, Marco; Quero, Giuseppe; Spaziani, Sara; Principe, Maria; Micco, Alberto; Galdi, Vincenzo; Cutolo, Antonello; Cusano, Andrea
• Is Part Of: Laser & photonics reviews. Volume 14:Issue 12(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-09-06
• Subjects: biomolecular sensing -- lab‐on‐fiber technology -- label‐free fiber optic biosensors -- optical fiber meta‐tips -- phase‐gradient metasurfaces; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.202000180
• Languages: English
• ISSNs: 1863-8880

Abstract

Abstract: The integration of metasurfaces on the tip of optical fibers enables advanced wavefront manipulations in Lab‐on‐Fiber application scenarios, and brings about new degrees of freedom that can be exploited for optimizing the surface sensitivity to local variations of the refractive index. Here, a novel biosensing platform is reported based on the integration of a phase‐gradient plasmonic metasurface on the tip of an optical fiber, able to detect biomolecular interactions with very high sensitivity. Specifically, the capability of the proposed platform to detect very low concentrations of streptavidin in running buffer solutions, with a limit of detection of the order of a few ng mL −1, is demonstrated. In addition, its inherent integrability within medical catheters/needles renders it potentially very attractive for application scenarios of real‐time diagnosis via liquid biopsy at precise locations inside the human body. Abstract : A "meta‐tip" optrode is proposed which integrates a plasmonic metasurface on the tip of an optical fiber, designed so as to impart a phase gradient that efficiently excites a surface wave. Via suitable biofunctionalization, the optrode can detect biomolecular (Biotin–Streptavidin) interactions in terms of wavelength shift in the reflectivity response. Results are of interest for real‐time diagnosis via liquid biopsy.