Conducting Polymers-Thylakoid Hybrid Materials for Water Oxidation and Photoelectric Conversion

Methods and materials to manage interfaces between organelles and nonbiological functional materials have the potential to impart organelles with new and enhanced functions. Here, a hybrid bio-photoelectrochemical system is designed by incorporating a cationic poly(fluorene-co-phenylene) conducting polymer (PFP) and thylakoids onto electrodes. PFP plays a critical role in boosting the efficiency of light energy conversion from the overall photoelectrochemical response. The positively charged side chains of PFP promote electrostatic binding with thylakoids, thereby improving the interfacial contact to the charge-collecting electrode. Furthermore, the optical absorption band of PFP is complementary to the absorption profile of thylakoids. Light utility efficiency is therefore increased through a process of energy transfer. Moreover, the redox potential of PFP matches well with that of the protein complexes in electron transport chain, which facilitates electron-transfer process from thylakoids to electrode. This combination of effects leads to a greater than 200% increase in the efficiency of water oxidation to oxygen. Under white light irradiation (350-800 nm, 50 mW cm(-2)), the photoelectric response of PFP/thylakoid electrode exhibits a photocurrent density of 1246 +/- 41 nA cm(-2), which is enhanced by approximately four times compared to that of the electrode modified only with thylakoid.