Electrostatic interaction regulated self-assembly of simple inorganic macroions into blackberry structures and their possible role as compartment systems in the origin of life

Blackberry structure is a type of universal, stable, porous, single layered, hollow, spherical supramolecular structure with sizes from tens to hundreds of nanometers self-assembled by various macroions (1-6 nm-size) in dilute solutions of water or other polar solvents. This self-assembly process is driven by counterion-mediated attraction, and merely requires ions to be large enough and moderately charged. The blackberry structures possess important features including their spontaneous and reversible self-assembly with tunable assembly sizes, capability of selectively segregating counterions, permeability to small counterions and molecules, self-recognition, as well as chiral recognition and selection. Considering such simple requirements for the self-assembly process and the mentioned features, and the availability of various macroions on the prebiotic earth, we will discuss about the possible role of blackberry structures as a compartmentalizing system in the origin of life concentrating the precursors and preparing proper conditions for the reaction to synthesize building blocks of early lives. We also speculate that they could have played a key role in the evolution of homochiral biological systems by intensifying the small enantiomeric imbalance, that might have existed on the prebiotic Earth.