This project aims to validate a novel plasmonic and dielectric structures for a considerable enhancement of fluorescent emission of a variety of fluorophores from the visible (VIS) to the near infrared (NIR) spectral domains, based on metasurfaces, and explore its applicability in biosensing. It is well known that the fluorescence (FL) of a molecule depends on its quantum properties and the environment due to the Purcell effect. The changes in the FL properties result as the interplay between radiative and non-radiative decay which depend on the form of the electromagnetic (EM) fields. A method to enhance the FL is the employment of nanoparticles although it is difficult to control accurately the fields in their proximity.

This project proposes an ample investigation of geometry and configurations of the nano-antennas focusing on achieving the highest resonance at various wavelengths, in VIS and NIR, for optimal fluorescence enhancement (FLEN). The fabrication of the structures will be realized using electron beam lithography (EBL) or deep-UV and lift-off method, and FL spectroscopy will assess the FLEN obtained. The metasurfaces based FLEN is a field in the pioneer stage, therefore, different metals and dielectrics, with various plasma frequencies, as well as substrates will be studied for the appropriate FLEN. Also, due to the interactions of the EM field with individual fluorophores, we will develop various geometries giving the EM configuration and resonance at various wavelengths prone to FLEN.

The FLEN is an important topic since it has a variety of applications in medical research and photonic devices.

The final aim will be to obtain nanostructures that have resonance modes corresponding both to the fluorescence absorption and emission spectra to improve the efficiency of the metasurface for fluorescence applications, and the functionalization of the metasurfaces and covalent immobilization of antibodies and proteins for experiments in biosensing application.