We present a novel imaging technique with super-resolution axial sensitivity, exploiting the changes in fluorescence lifetime above a plasmonic substrate. Using conventional confocal fluorescence lifetime imaging, we show that it is possible to deliver down to 6 nm axial position sensitivity of fluorophores in whole biological cell imaging. We employ this technique to map the topography of the cellular membrane, and demonstrate its application in an investigation of receptor-mediated endocytosis in carcinoma cells.
Mapping the Spatiotemporal Heterogeneity of Biomolecules Concentration, Mobility and Local Environment in Live Cells using Quantitative Time-Resolved Confocal Fluorescence Microscopy Imaging Without Scanning and Fluorescence Lifetime Imaging Microscopy
