Polyelectrolyte adsorption onto like-charged surfaces mediated by trivalent counterions: A Monte Carlo simulation study

Abstract

Both experiments and theory have evidenced that multivalent cations can mediate the interaction between negatively charged polyelectrolytes and like-charged objects, such as anionic lipoplexes (DNA-cation-anionic liposome complexes). In this paper, we use Monte Carlo simulations to study the electrostatic interaction responsible for the trivalent-counterion-mediated adsorption of polyelectrolytes onto a like-charged planar surface. The evaluation of the Helmholtz free energy allows us to characterize both the magnitude and the range of the interaction as a function of the polyelectrolyte charge, surface charge density, [3:1] electrolyte concentration, and cation size. Both polyelectrolyte and surface charge favor the adsorption. It should be stressed, however, that the adsorption will be negligible if the surface charge density does not exceed a threshold value. The effect of the [3:1] electrolyte concentration has also been analyzed. In certain range of concentrations, the counterion-mediated attraction seems to be independent of this parameter, whereas very high concentrations of salt weaken the adsorption. If the trivalent cation diameter is doubled the adsorption moderates due to the excluded volume effects. The analysis of the integrated charge density and ionic distributions suggests that a delicate balance between charge inversion and screening effects governs the polyelectrolyte adsorption onto like-charged surfaces mediated by trivalent cations.

Simulations of Polyelectrolyte Adsorption to a Dielectric Like-Charged Surface

“…However, only recently some groups have started to explore the interaction between polyelectrolyte and like-charged membranes. [31][32][33] This study can lead to important applications in future.…”

Like-charged protein-polyelectrolyte complexation driven by charge patches

“…Besides experimental efforts, 8,9 various theoretical approaches [10][11][12][13][14][15] and computer simulation analyses [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] were introduced to explain the formation and structure of protein-PE complexes. Most of the theoretical investigations are focused on the interaction between a PE chain and oppositely charged macromolecules, driven essentially by the leading order monopole electrostatic attraction.…”

Critical adsorption of polyelectrolytes onto charged Janus nanospheres

“…[14,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. The regime of weak PE-surface adsorption for which the entropy of the PE chain is still important, was extensively studied by computer simulations [32][33][34][35][36][37][38][39][40][41][42][43][44]. The characteristics of the PE-surface adsorption including the conditions for the critical adsorption of long PE chains with a constant linear charge density onto planar [45,46] and curved [14,[47][48][49][50][51][52][53][54][55][56][57][58] interfaces were also derived.…”