Spectral distortions in zinc-based metal-enhanced fluorescence underpinned by fast and slow electronic transitions

Metal-enhanced fluorescence (MEF) is a promising technology with impact in diagnostics, electronics, and sensing. Despite investigation into MEF fundamentals, some properties remain unresearched, notably spectral distortion. To date, publications have described its underpinnings, yet comprehensive analysis is needed, as presented recently for silver films. Herein we expand this description using zinc substrates (ZnNPs). Significant red-edge and blue-edge distortions are reported using Rose Bengal. Radiative decay rate modification is identified as key in amplifying fast/slow electronic transitions by the enhanced emission mechanism. Furthermore, we identify distortion in published studies, bolstering our thinking that spectral distortion is an intrinsic property of MEF.