Nontrivial effects of dielectric mismatch on the conformational behavior of confined polyelectrolytes

We investigate the conformational behavior of a highly charged polyelectrolyte confined in a spherical cavity where the media inside and outside the cavity have different dielectric constants. Depending on the charge density of the cavity surface and dielectric mismatch, the polyelectrolyte either collapses into amorphous conformations, or folds into a four-fold symmetry conformation. On the contrary to the common wisdom that polarization effects would be negligible for charged surfaces, we find that such effects influence the polyelectrolyte conformational behavior in a nontrivial manner. Our study provides insight into the effects of dielectric mismatch in packaging and delivery of polyelectrolytes across media with different relative permittivities. Moreover, the reversible transformation of the polyelectrolyte conformations in response to environmental permittivity suggests potential applications in biosensing and medical monitoring.