Photo-Electrochemical Osmotic Drive: A Model for Physical Evolution of Protocells via Nanoparticle-Mediated Cannibalism

This paper proposes a novel framework for prebiotic protocell evolution that addresses a critical flaw in passive growth models (e.g., the Szostak model): the dilution of internal osmolytes following vesicle division. We hypothesize that semiconductor nanoparticles (e.g., FeS, ZnS, TiO2) embedded within fatty acid (FA) membranes act as photovoltaic transducers. Upon photon absorption, these nanoparticles generate charge carriers that partially oxidize fatty acid chains into hydrophilic fragments. These fragments, acting as internal osmolytes, increase the internal osmotic pressure (turgor), driving vesicle expansion and the competitive acquisition of membrane material from less active neighbors. This "osmotic cannibalism" establishes a system of physical selection where only vesicles with an optimal balance between metabolic output and structural integrity survive and divide.