Large-Area Metasurfaces for Enhanced Fluorescence Imaging

Abstract All-dielectric metasurfaces have been extensively applied to three-dimensional displays, vortex beam generation, beam steering, and luminescence enhancement. However, studies on all-dielectric metasurfaces for enhancing biofluorescence imaging remain relatively scarce. In this study, an anodic aluminum oxide (AAO) template is employed to fabricate a large-area silicon metasurface embedded in PDMS to serve as a fluorescence imaging slide. Under the excitation of the electromagnetic dipole resonance of metasurface, the cells stained with iFluor 555-phalloidin on the metasurface film exhibit a fluorescence enhancement potentially arising from the combined contributions of Purcell-related radiative decay-rate modification, local excitation-field enhancement, and changes in fluorescence collection efficiency, substantially improving the fluorescence imaging quality. The experimental results demonstrate that when the silicon metasurface embedded in PDMS serves as a fluorescence imaging slide, the fluorescence imaging intensity is enhanced by a factor of approximately 3.38. To the best of our knowledge, this is the first demonstration of large-area all-dielectric metasurfaces fabricated via the AAO template method for enhanced fluorescence imaging. This finding broadens the scope of all-dielectric metasurfaces with large area for biomedical fluorescence imaging.