“…19 With respect to the dielectric space layer, the materials involved in majority of published work are inert silica shell, [20][21][22] polyelectrolyte multilayers obtained by layer-by-layer (LBL) technique, 23,24 polymers, 25,26 or prototypical biomolecules (D-biotin, complementary DNA or streptavidin pairs). 27,28 Although the local distance between plasmonic nanostructures and uorophores can be controlled by using these space layers, the attachment of uorophores on the surface of plasmonic structures is either difficult, time consuming or unstable as uorophores are basically incorporated with plasmonic nanostructures via non-covalent interaction or physical adsorption methods, [29][30][31] which would inevitably limit the practical application of PEF in harsh conditions (e.g. high temperature, strong acid medium, etc.)…”