Plasmonics has been recognized as a simple and highly effective approach for enhancing fluorescence. Enhancement of the emission of fluorophores in close proximity to plasmonic nanostructures is attributed to the enhanced electromagnetic field (local excitation field) at the surface of the plasmonic nanostructures and the decrease in the fluorescence lifetime due to the coupling between the excited fluorophores and the surface plasmons of the nanostructures8,9,10,11,12,13,14,15,16,17. To date, various plasmonic substrates, such as periodic gold arrays18,19 and metal nanoislands11,12,13,14, have been shown to give rise to strong fluorescence enhancement. Although these plasmonic surfaces are highly attractive, their real-world application, for example, in fluoroimmunoassays, has been limited. The limited application of plasmon-enhanced fluoroimmunoassays in research and clinical settings is due to several factors: (i) Most of the existing techniques require the fluoroimmunoassay to be performed on pre-fabricated substrates, typically a rigid glass slide with metal nanostructures deposited on it, instead of standard or sometimes irreplaceable bioanalytical platforms (e.g., 96-well plates and nitrocellulose membranes), which significantly limits the broad applicability of the techniques; more importantly, the requirement for the use of special substrates limits cross-platform and cross-laboratory consistency and seamless integration with widely employed bioanalytical procedures, representing a major bottleneck for the exploitation of conventional plasmon-enhanced fluorescence. (ii) Non-traditional bioconjugation procedures, complex interactions between biomolecules and metal nanostructures, and poor stability of biomolecules (e.g., antibodies) immobilized on metal surfaces not only complicate the assay procedures but also impose further technical challenges in their widespread application20. Thus, it is imperative to address these challenges to propel the plasmon-enhanced fluorescence techniques to practical applications.