Depth-tunable vibration-induced emission probes map spatial viscosity heterogeneity and dynamics in cell membrane.

Two depth-tunable vibration-induced emission probes, DPAC-2C and DPAC-6C, were developed to map spatial microviscosity gradients across lipid bilayers. Overcoming traditional limitations of average viscosity reporting, the probes enable precise, spatially resolved ratiometric monitoring of depth-dependent viscosity and cholesterol-induced dynamics in live cell membranes.