2023 BIST Ignite Project: DendriPhotoSomes

Chloroplast-mimetic dendrimersome: toward artificial photosynthesis

Project overview

Artificial Photosyntesis (AP) holds promise as a means to harness solar energy and convert it in chemical fuels. In nature, this process takes place in the thylakoid membrane of chloroplasts, an organelle composed by a stack of interconnected membranes which confines the catalytic centres and light harvesters and separates the two half-redox reactions achieving an effective charge separation state. Unilamellar liposomes have been used to mimic this compartmentalization, however, their poor chemical and mechanical stability posed challenges towards the realization of AP. Moreover, lipid amphiphiles provide only a simple and thin bilayer compared to the complex architecture of thylakoid membrane operating in natural systems. Some synthetic alternatives, such as the use of polymersomes based on macromolecular amphiphiles have been tentatively proposed so far. However, these membranes show low substrate permeability, limited flexibility and slow diffusion properties.

DendriPhotoSomes project proposes the use of dendrimersomes based on Janus dendrimers to circumvent the limitations stated above. The project combines the expertise of Ballester’s (ICIQ) and Rodriguez Emmenegger’s (IBEC) teams to prepare unprecedented photoactive (catalytic) thylakoid-mimetic dendrimersomes (photoDSs) featuring excellent chemical, mechanical and thermal stability and good membrane permeability and flexibility.

The novelty behind DendriPhotoSomes project lies in the connection of the research devoted to the preparation of efficient photocatalyst and photosensitizers for AP (e.g. CO2RR) with the know-how in the preparation of robust vesicles able to confine and separate AP redox half-reactions to avoid cross-reactivity. The interdisciplinary nature of the team provides the necessary knowledge to develop improved AP models and study their photocatalytic properties, first in CO2RR (seeding phase) and later in water oxidation (WO).