Spacer and Cavity Engineering on Low-cost Plastic Substrates for 100-Fold Enhancements in Metal-Dielectric-Metal-Based Directional Fluorescence Emission

Surface plasmon-based techniques have gained momentum in the last decade due to their ability to improve inherent drawbacks of conventional fluorescence. One such recent advancement utilizes metal-dielectric-metal (MDM) substrates. In this work, we report the use of the spacer and cavity engineering in MDM on plastic substrates for fluorescent signal enhancement. Furthermore, the use of low-dimensional carbon materials as spacers and cavities resulted in ~ 100-fold enhancement in MDM-steered fluorescence emission.