Pre-Label-Free Three-Dimensional Imaging of Cellular Bottom Topography with a Charge-Lock Electrochemiluminescence Microscope

Cellular bottom structure plays a vital role in cell mobility, but its narrow space makes it difficult to study. Currently, it remains challenging to panoramically map the cellular bottom topography variations due to the potential cellular damage and off-target effects of luminophores when using current ultra-high-resolution optical microscopy. Here, we present charge-lock spatiotemporal transformation electrochemiluminescence (CL-STTECL) microscopy. The ECL is "locked" by the charge exclusion between cationic luminophores and the proton film, while amine co-reactants simultaneously "unlock" this process. Consequently, the uneven distribution of luminophores at the cellular base triggers a gap distance-dependent ECL emission trajectory, allowing the identification of cell-matrix gap distance heterogeneity at an axial spatial resolution of ∼10 nm. Using CL-STTECL microscopy, we demonstrated changes in cellular bottom topography in response to various external stimulations and uncovered heterogeneity in panoramic features between normal tissue cells and metastatic cancer cells, offering a novel approach for early cancer screening.