Fig. 3.

Approach and penetration of an MCF-10A cell by a 144-nm tip in PBS solution containing 1 mM FcCH₂OH (A) and steady-state voltammograms obtained at the same tip outside (curve 1) and inside (curve 2) the cell (B). (A Inset) Shown is the fit between the experiment (symbols) and the theory (solid line) for the final part of the curve, where the tip approaches the bottom of the Petri dish.