Gallium phosphide nanoantenna controls enhanced single-molecule fluorescence

We propose a design for all-dielectric (gallium phosphide, GaP) nanoantenna to enhance single molecule fluorescence. The slotted GaP nanodisk exhibits strong scattering and limited optical loss, resulting in more than 30× excitation enhancement growth at the resonance position. Our proposed scheme also enables precise manipulation of the local density of optical states, leading to a nearly one order of magnitude increments in quantum yield for individual dye (original quantum yield is 0.01) and 12× emission enhancement. We benchmark the overall fluorescent enhancement for the four commercial dye colors (original quantum yield is 0.3) and achieved one-order of enhancement higher than commercialized zero-mode waveguide (ZMW) in the simulation. Our GaP-based design not only provides a solution for next-generation chips for DNA and protein sequencing, but also contributes to single-entity interactions, portable fluorescence detection, and integrated devices with quantum light sources.