Research Article

Enhancing fluorescence of low quantum yield fluorophores with plasmonic metasurfaces

National Institute for Research and Development in Microtechnology – IMT Bucharest, 126A, Erou Iancu Nicolae Street, 077190, Voluntari, Ilfov, Romania

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Received: 30 January 2026
Accepted: 4 March 2026

Abstract

Metasurfaces represent an innovative category of optical surfaces that can be engineered to exhibit distinctive properties that are not observed in conventional materials. It has been demonstrated that these structures exhibit robust light-matter interactions at the nanoscale, which renders them a promising solution for enhancing the sensitivity of various biomedical sensing technologies. This work presents a versatile approach for enhancing the broadband spectral emission of various fluorophores. The approach involves developing large-area, lithography-free plasmonic platforms without tailoring the geometry of the metasurface to a specific chromophore. The investigation encompasses the fluorescence behaviour of low quantum yields fluorophores such as Crystal Violet, Nile Red, and Rose Bengal, dispersed in ethanol solutions and coated onto the metallic arrays with random configuration. The results indicate that metallic nanostructures efficiently support plasmon-mediated fluorescence enhancement, and the degree of this enhancement depends strongly on both the fluorophore type and the metal layer thickness. The highest fluorescent enhancement factor was obtained for Crystal Violet on silver metasurfaces.