Lipid bilayer-mediated spatiotemporal correlation between near-wall confined motion of micro-carriers

Abstract

We employed intensity fluctuations of evanescent light scattering to probe spatiotemporal correlations in the near-wall confined motion of microspheres on supported lipid bilayers (SLBs). Normalized cross-correlation analysis revealed long-range, time-resolved correlations in particle–wall separation distances, demonstrating that interfacial stress propagation can transmit mechanical signals across membrane interfaces. The motion exhibited broadly corralled diffusion, with both the corral size and diffusion constant confined to the nanoscale. This confinement could be further classified into fast and slow modes, with most diffusion constants residing in the slow regime, indicating that SLBs predominantly retard and localize microsphere dynamics at the interface. Furthermore, a transition in the interbilayer interaction profile—from bimodal to single-peak behavior—introduced a characteristic length scale and a kT-scale energy barrier, underscoring the cooperative interplay between interfacial stress propagation and membrane shape remodeling.